login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A151948 a(n) = tau(sigma(phi(n))). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

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

CROSSREFS

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

Sequence in context: A164126 A261902 A163368 * A080400 A119462 A293221

Adjacent sequences:  A151945 A151946 A151947 * A151949 A151950 A151951

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Jul 20 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 15 13:27 EST 2018. Contains 318149 sequences. (Running on oeis4.)