A067161 a(n) = prime(sigma(n)).

2, 5, 7, 17, 13, 37, 19, 47, 41, 61, 37, 107, 43, 89, 89, 127, 61, 167, 71, 181, 131, 151, 89, 281, 127, 181, 173, 263, 113, 359, 131, 307, 223, 251, 223, 467, 163, 281, 263, 463, 181, 503, 193, 433, 397, 359, 223, 683, 269, 487, 359, 521, 251, 659, 359, 659

Offset: 1

Author

Benoit Cloitre, Feb 19 2002

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000040, A000203, A072677.

Programs

Mathematica

Prime[DivisorSigma[1,Range[60]]] (* Harvey P. Dale, May 10 2013  *)

PARI

A067161(n) = prime(sigma(n)); \\ Antti Karttunen, Nov 16 2017

Formula

a(n) = A000040(A000203(n)).

a(A000040(n)) = A072677(n). - Michael B. Porter, Nov 18 2017