A163075 Primes of the form k$ + 1. Here '$' denotes the swinging factorial function (A056040).

2, 3, 7, 31, 71, 631, 3433, 51481, 2704157, 280816201, 4808643121, 35345263801, 2104098963721, 94684453367401, 1580132580471901, 483701705079089804581, 6892620648693261354601, 410795449442059149332177041, 2522283613639104833370312431401

Offset

1,1

Links

Jinyuan Wang, Table of n, a(n) for n = 1..50

Peter Luschny, Die schwingende Fakultät und Orbitalsysteme, August 2011.

Peter Luschny, Swinging Primes.

Example

Since 3$ = 4$ = 6 the prime 7 is listed, however only once.

Maple

a := proc(n) select(isprime, map(x -> A056040(x)+1, [$1..n])) end:

Mathematica

Reap[Do[f = n!/Quotient[n, 2]!^2; If[PrimeQ[p = f + 1], Sow[p]], {n, 1, 70}]][[2, 1]] // Union (* Jean-François Alcover, Jun 28 2013 *)

Crossrefs

Cf. A056040, A088332, A163077 (arguments k), A163074, A163076.

Sequence in context: A008840 A268477 A156313 * A265113 A228171 A089359

Adjacent sequences: A163072 A163073 A163074 * A163076 A163077 A163078

Keyword

nonn

Author

Peter Luschny, Jul 21 2009

Extensions

More terms from Jinyuan Wang, Mar 22 2020

Status

approved