The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A063955 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A063955

Sum of the unitary prime divisors of n!.
(history; published version)

#27 by Alois P. Heinz at Wed Jul 24 21:08:31 EDT 2024

STATUS

proposed

approved

#26 by Amiram Eldar at Wed Jul 24 03:24:13 EDT 2024

STATUS

editing

proposed

#25 by Amiram Eldar at Wed Jul 24 03:02:12 EDT 2024

CROSSREFS

Cf. A010051, A034387, A034444, A056169, A056170, A056171, A056172, A063956.

#24 by Amiram Eldar at Wed Jul 24 02:59:48 EDT 2024

CROSSREFS

Cf. A010051, A034387, A034444, A056169, A056170, A056171, A056172, A034387, A034444.

#23 by Amiram Eldar at Wed Jul 24 02:59:16 EDT 2024

EXAMPLE

Prime factors in divisors of 20! which have exponent= 1 (i.e., unitary p-prime divisors) are {11, 13, 17, 19}; sum = 60, , so a(20) = 11 + 13 + 17 + 19= 60. (The sum of all its prime factors divisors (unitary and non-unitary) is A034387(20).)

#22 by Amiram Eldar at Wed Jul 24 02:57:00 EDT 2024

NAME

Sum of the unitary prime divisors (A056169, A056171) of n!.

#21 by Amiram Eldar at Wed Jul 24 02:55:36 EDT 2024

FORMULA

a(n) = A063956(n!). - Amiram Eldar, Jul 24 2024

STATUS

approved

editing

#20 by Wesley Ivan Hurt at Sat Dec 23 22:30:03 EST 2023

STATUS

editing

approved

#19 by Wesley Ivan Hurt at Sat Dec 23 22:29:24 EST 2023

NAME

Sum of the unitary prime divisors (A056169, A056171) of n!.

FORMULA

a(n) = Sum_{k=floor(n/2)+1..n} k*c(k), where c is the prime characteristic (A010051). - Wesley Ivan Hurt, Dec 23 2023

CROSSREFS

Cf. A010051, A056169, A056170, A056171, A056172, A034387, A034444.

KEYWORD

nonn,easy

STATUS

approved

editing

#18 by OEIS Server at Sat Jan 01 18:00:13 EST 2022

LINKS

Alois P. Heinz, <a href="/A063955/b063955_1.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Harry J. Smith)