login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A305794
a(n) = Product_{d|n, d>1} prime(A286622(d)-1).
4
1, 2, 3, 4, 5, 18, 7, 8, 15, 50, 11, 108, 11, 98, 195, 16, 5, 450, 11, 500, 357, 242, 19, 648, 55, 242, 345, 1372, 19, 76050, 29, 32, 165, 50, 385, 13500, 17, 242, 627, 5000, 17, 254898, 31, 5324, 30225, 722, 37, 3888, 77, 6050, 345, 5324, 31, 238050, 2255, 19208, 627, 722, 41, 29659500, 37, 1682, 76755, 64, 275, 54450, 11, 500, 969, 296450, 19, 405000, 17
OFFSET
1,2
LINKS
FORMULA
a(n) = Product_{d|n, d>1} A008578(A286622(d)).
For all k >= 0, a(2^k) = 2^k.
PROG
(PARI) A305794(n) = { my(m=1); fordiv(n, d, if(d>1, m *= prime(A286622(d)-1))); (m); }; \\ Needs also code from A286622.
CROSSREFS
Cf. A008578, A278222, A286622, A305792, A305795 (rgs-transform).
Cf. also A304104.
Sequence in context: A375638 A162657 A333046 * A317944 A145520 A337559
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 11 2018
STATUS
approved