The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A336121 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A336121

a(1) = 0, and for n > 1, a(n) = [A122111(n) == 3 (mod 4)] + a(A253553(n)).
(history; published version)

#9 by Susanna Cuyler at Fri Jul 17 22:57:33 EDT 2020

STATUS

proposed

approved

#8 by Antti Karttunen at Fri Jul 17 15:27:48 EDT 2020

STATUS

editing

proposed

#7 by Antti Karttunen at Fri Jul 17 15:27:25 EDT 2020

COMMENTS

Positions for the first occurrence of each n, for n >= 0, are: 1, 4, 16, 32, 144, 512, 2048, 6912, 20736, 62208, ...

#6 by Antti Karttunen at Fri Jul 17 15:26:54 EDT 2020

COMMENTS

Positions for the first occurrence of each n, for n >=0.. , are: 1, 4, 16, 32, 144, 512, 2048, 6912, 20736, 62208, ...

FORMULA

a(1) = 0, and for n > 1, a(n) = [A122111A336124(n) == 3 (mod 4)] + a(A253553(n)).

#5 by Antti Karttunen at Fri Jul 17 09:47:50 EDT 2020

FORMULA

a(n) = A001222(n) - A336123(n).

CROSSREFS

Cf. A000120, A001222, A122111, A253553, A292377, A292383, A336120, A336123, A336124.

#4 by Antti Karttunen at Fri Jul 17 08:27:18 EDT 2020

COMMENTS

Positions for the first occurrence of each n, for n=0.. are: 1, 4, 16, 32, 144, 512, 2048, 6912, 20736, 62208, ...

LINKS

Antti Karttunen, <a href="/A336121/b336121.txt">Table of n, a(n) for n = 1..65537</a>

#3 by Antti Karttunen at Fri Jul 17 06:42:17 EDT 2020

FORMULA

a(n) = A292377(A122111(n)).

CROSSREFS

Cf. A000120, A122111, A253553, A292377, A292383, A336120, A336124.

#2 by Antti Karttunen at Fri Jul 17 06:39:12 EDT 2020

NAME

allocated a(1) = 0, and for Antti Karttunenn > 1, a(n) = [A122111(n) == 3 (mod 4)] + a(A253553(n)).

DATA

0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 0, 2, 1, 1, 0, 1, 0, 2, 0, 3, 0, 1, 1, 1, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 0, 3, 0, 1, 0, 1, 0, 3, 1, 2, 0, 1, 0, 1, 0, 1, 0, 3, 1, 2, 0, 1, 0, 1, 0, 2, 0, 1, 1, 1, 0, 2, 0, 3, 0, 1, 0, 1, 1, 1, 0, 2, 0, 3, 0, 1, 0, 1, 1, 3, 0, 2, 0, 2, 0, 2, 0, 2, 1

OFFSET

1,16

FORMULA

a(1) = 0, and for n > 1, a(n) = [A122111(n) == 3 (mod 4)] + a(A253553(n)).

a(n) = A000120(A336120(n)).

PROG

(PARI)

A253553(n) = if(n<=2, 1, my(f=factor(n), k=#f~); if(f[k, 2]>1, f[k, 2]--, f[k, 1] = precprime(f[k, 1]-1)); factorback(f));

A336121(n) = if(1==n, 0, (3==A336124(n))+A336121(A253553(n)));

CROSSREFS

Cf. A000120, A122111, A253553, A292383, A336120, A336124.

Cf. A336119 (positions of zeros).

KEYWORD

allocated

nonn

AUTHOR

Antti Karttunen, Jul 17 2020

STATUS

approved

editing

#1 by Antti Karttunen at Thu Jul 09 06:21:46 EDT 2020

NAME

allocated for Antti Karttunen

KEYWORD

allocated

STATUS

approved