The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A151948

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A151948

a(n) = tau(sigma(phi(n))).
(history; published version)

#9 by Bruno Berselli at Wed Aug 23 06:11:22 EDT 2017

STATUS

proposed

approved

#8 by Antti Karttunen at Tue Aug 22 12:54:13 EDT 2017

STATUS

editing

proposed

#7 by Antti Karttunen at Tue Aug 22 12:42:01 EDT 2017

CROSSREFS

Cf. A000005, A000010, A000203, A062068, A062402, A163375.

#6 by Antti Karttunen at Tue Aug 22 12:40:51 EDT 2017

CROSSREFS

Cf. A000005, A000010, A000203, A062068, A062402.

#5 by Antti Karttunen at Tue Aug 22 12:39:11 EDT 2017

COMMENTS

a(n) = A000005(A000203(A000010(n))) = A000005(A062402(n)) = A062068(A000010(n)).

LINKS

Antti Karttunen, <a href="/A151948/b151948.txt">Table of n, a(n) for n = 1..10000</a>

FORMULA

a(n) = A000005(A000203(A000010(n))) = A000005(A062402(n)) = A062068(A000010(n)).

PROG

(PARI) A151948(n) = numdiv(sigma(eulerphi(n))); \\ Antti Karttunen, Aug 22 2017

STATUS

approved

editing

#4 by Alois P. Heinz at Tue Jan 31 19:44:44 EST 2017

STATUS

editing

approved

#3 by Alois P. Heinz at Tue Jan 31 19:44:30 EST 2017

NAME

a(n) = tau (sigma (phi (n))).

DATA

1, 1, 2, 2, 2, 2, 6, 2, 6, 2, 6, 2, 6, 6, 4, 4, 2, 6, 4, 4, 6, 6, 9, 4, 8, 6, 4, 6, 8, 4, 12, 2, 8, 2, 12, 6, 4, 4, 12, 2, 12, 6, 12, 8, 12, 9, 12, 2, 12, 8, 6, 12, 6, 4, 12, 12, 4, 8, 12, 2, 16, 12, 4, 6, 6, 8, 15, 6, 12, 12, 15, 12, 8, 4, 12, 4, 16, 12, 16

STATUS

approved

editing

Discussion

Tue Jan 31

19:44

Alois P. Heinz: ...

#2 by Russ Cox at Fri Mar 30 19:00:15 EDT 2012

AUTHOR

_Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), _, Jul 20 2009

Discussion

Fri Mar 30

19:00

OEIS Server: https://oeis.org/edit/global/299

#1 by N. J. A. Sloane at Tue Jun 01 03:00:00 EDT 2010

NAME

tau (sigma (phi (n))).

DATA

1, 1, 2, 2, 2, 2, 6, 2, 6, 2, 6, 2, 6, 6, 4, 4, 2, 6, 4, 4, 6, 6, 9, 4, 8, 6, 4, 6, 8, 4, 12, 2, 8, 2, 12, 6, 4, 4, 12, 2, 12, 6, 12, 8, 12, 9, 12, 2, 12, 8

OFFSET

1,3

COMMENTS

a(n) = A000005(A000203(A000010(n))) = A000005(A062402(n)) = A062068(A000010(n)).

KEYWORD

nonn

AUTHOR

Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Jul 20 2009

STATUS

approved