A317942 a(n) = Product_{d|n, d<n} prime(A286378(d)-1).

1, 2, 2, 4, 2, 12, 2, 8, 6, 20, 2, 72, 2, 28, 30, 16, 2, 396, 2, 200, 42, 52, 2, 432, 10, 68, 66, 392, 2, 17100, 2, 32, 78, 92, 70, 26136, 2, 116, 102, 2000, 2, 54684, 2, 1352, 6270, 148, 2, 2592, 14, 3700, 138, 2312, 2, 178596, 130, 5488, 174, 172, 2, 9747000, 2, 188, 14322, 64, 170, 322452, 2, 4232, 222, 289100, 2, 1724976, 2

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..8192

Index entries for sequences related to Stern's sequences

Formula

a(n) = Product_{d|n, d<n} A008578(A286378(d)).

For all k >= 0, a(2^k) = 2^k.

Prog

(PARI)
\\ Needs also code from A286378:
A317942(n) = { my(m=1); fordiv(n, d, if(d<n, m *= prime(A286378(d)-1))); (m); };

Crossrefs

Cf. A286378, A317943 (restricted growth sequence transform), A317944.

Cf. also A293216, A305792.

Sequence in context: A329600 A344226 A305792 * A296071 A319342 A318834

Adjacent sequences: A317939 A317940 A317941 * A317943 A317944 A317945

Keyword

nonn

Author

Antti Karttunen, Aug 12 2018

Status

approved