login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A166648 Totally multiplicative sequence with a(p) = 8*(p+1) for prime p. 1
1, 24, 32, 576, 48, 768, 64, 13824, 1024, 1152, 96, 18432, 112, 1536, 1536, 331776, 144, 24576, 160, 27648, 2048, 2304, 192, 442368, 2304, 2688, 32768, 36864, 240, 36864, 256, 7962624, 3072, 3456, 3072, 589824, 304, 3840, 3584, 663552, 336, 49152 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

FORMULA

Multiplicative with a(p^e) = (8*(p+1))^e. If n = Product p(k)^e(k) then a(n) = Product (8*(p(k)+1)^e(k). a(n) = A165829(n) * A003959(n) = 8^bigomega(n) * A003959(n) = 8^A001222(n) * A003959(n).

MATHEMATICA

a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] + 1)^fi[[All, 2]])); Table[a[n]*8^(PrimeOmega[n]), {n, 1, 100}] (* G. C. Greubel, May 21 2016 *)

PROG

(PARI) a(n) = {my(f = factor(n)); for (k=1, #f~, f[k, 1] = 8*(f[k, 1]+1)); factorback(f); } \\ Michel Marcus, May 21 2016

CROSSREFS

Sequence in context: A319928 A025102 A188671 * A231468 A179188 A102505

Adjacent sequences:  A166645 A166646 A166647 * A166649 A166650 A166651

KEYWORD

nonn,mult

AUTHOR

Jaroslav Krizek, Oct 18 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 August 10 08:28 EDT 2020. Contains 336368 sequences. (Running on oeis4.)