A128456 Quotients A128452(p+1)/p for prime p = A000040(n).

2, 7, 311, 127, 23, 157, 7563707819165039903, 75368484119, 47, 9629, 311, 25679, 821, 758771382833029, 12409, 71233, 18438666190697, 2443783, 2939291, 71711, 352883, 181113265579, 167, 105199, 3881, 1314520253, 619, 20759, 117503, 1162660843

Offset

1,1

Comments

a(n) coincides with A128357(n) from n = 2 up to n = 6.

Links

Table of n, a(n) for n=1..30.

Formula

a(n) = A128452(A000040(n)+1)/A000040(n).

a(n) = A020639(((p+1)^p - 1)/p^2), i.e., the smallest prime factor of ((p+1)^p - 1)/p^2, where p = A000040(n).

Crossrefs

Cf. A128452, A128357, A128356, A127103, A127104, A127105, A127106, A127107, A127102, A127101, A127100, A127092, A128393, A128394, A128395, A128396, A128397, A128398, A128399, A128400, A128401, A128402, A128403, A128404.

Sequence in context: A290637 A260967 A367788 * A137666 A137665 A128466

Adjacent sequences: A128453 A128454 A128455 * A128457 A128458 A128459

Keyword

nonn

Author

Alexander Adamchuk, Mar 05 2007, Mar 09 2007

Extensions

Terms a(14) onward from Max Alekseyev, May 05 2010

Status

approved