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Revision History for A346697 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

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Sum of the odd-indexed parts (odd bisection) of the multiset of prime indices of n.
(history; published version)
#8 by Susanna Cuyler at Mon Aug 02 07:56:45 EDT 2021
STATUS

proposed

approved

#7 by Gus Wiseman at Sun Aug 01 16:43:17 EDT 2021
STATUS

editing

proposed

#6 by Gus Wiseman at Sun Aug 01 16:43:08 EDT 2021
#5 by Gus Wiseman at Sun Aug 01 15:57:37 EDT 2021
CROSSREFS

A344617 gives the sign of a(n) - A346698(n).

#4 by Gus Wiseman at Sun Aug 01 15:56:26 EDT 2021
CROSSREFS

A000120 (ones) and A080791 (zeros) count binary digits, 1 and 0, with difference A145037.

A344617 gives the sign of a(n) - A346698(n) (alternating sum of prime indices).

Cf. `A000070, ~A000097 ptns_altsum_2, A025047, ~A035363, A088218, `A097805, `A120452, A341446, ~A343941 strptns_ev_sats4, `A344604 alt_comps, `A344605 alt_normseq, A344614, A344653, `A344654 ptn_no_alt_perm, `A344741, A345957, A345958, A345959, ~A345960 prix_ats_2, ~A345961 prix_sats_2, ~A345962 prix_ats_neg2.

Cf. A000070, A025047, A088218, A120452, A341446, A344614, A344617, A344653, A344654, A345957, A345958, A345959.

#3 by Gus Wiseman at Sun Aug 01 02:42:18 EDT 2021
NAME

allocated for Gus WisemanSum of the odd-indexed parts (odd bisection) of the multiset of prime indices of n.

DATA

0, 1, 2, 1, 3, 1, 4, 2, 2, 1, 5, 3, 6, 1, 2, 2, 7, 3, 8, 4, 2, 1, 9, 2, 3, 1, 4, 5, 10, 4, 11, 3, 2, 1, 3, 3, 12, 1, 2, 2, 13, 5, 14, 6, 5, 1, 15, 4, 4, 4, 2, 7, 16, 3, 3, 2, 2, 1, 17, 3, 18, 1, 6, 3, 3, 6, 19, 8, 2, 5, 20, 4, 21, 1, 5, 9, 4, 7, 22, 5, 4, 1

OFFSET

1,3

COMMENTS

A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.

FORMULA

a(n) = A056239(n) - A346698(n).

a(n) = A316524(n) + A346698(n).

a(n odd omega) = A346699(n).

a(n even omega) = A346700(n).

A344616(n) = A346699(n) - A346700(n).

EXAMPLE

The prime indices of 1100 are {1,1,3,3,5}, so a(1100) = 1 + 3 + 5 = 9.

The prime indices of 2100 are {1,1,2,3,3,4}, so a(2100) = 1 + 2 + 3 = 6.

MATHEMATICA

primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];

Table[Total[First/@Partition[Append[primeMS[n], 0], 2]], {n, 100}]

CROSSREFS

The version for standard compositions is A209281(n+1) (even: A346633).

Subtracting the even version gives A316524 (reverse: A344616).

The even version is A346698.

The reverse version is A346699.

The even reverse version is A346700.

A000120 (ones) and A080791 (zeros) count binary digits, with difference A145037.

A000302 counts compositions with odd alternating sum, ranked by A053738.

A001414 adds up prime factors, row sums of A027746.

A029837 adds up parts of standard compositions (alternating: A124754).

A056239 adds up prime indices, row sums of A112798.

A103919 counts partitions by sum and alternating sum (reverse: A344612).

A325534 counts separable partitions, ranked by A335433.

A325535 counts inseparable partitions, ranked by A335448.

A344606 counts alternating permutations of prime indices.

A344617 gives the sign of a(n)-A346698(n) (alternating sum of prime indices).

Cf. `A000070, ~A000097 ptns_altsum_2, A025047, ~A035363, A088218, `A097805, `A120452, A341446, ~A343941 strptns_ev_sats4, `A344604 alt_comps, `A344605 alt_normseq, A344614, A344653, `A344654 ptn_no_alt_perm, `A344741, A345957, A345958, A345959, ~A345960 prix_ats_2, ~A345961 prix_sats_2, ~A345962 prix_ats_neg2.

KEYWORD

allocated

nonn

AUTHOR

Gus Wiseman, Aug 01 2021

STATUS

approved

editing

#2 by Gus Wiseman at Thu Jul 29 16:39:22 EDT 2021
KEYWORD

allocating

allocated

#1 by Gus Wiseman at Thu Jul 29 16:39:22 EDT 2021
NAME

allocated for Gus Wiseman

KEYWORD

allocating

STATUS

approved