A152678 - OEIS

A152678

Even members of A000203.

4, 6, 12, 8, 18, 12, 28, 14, 24, 24, 18, 20, 42, 32, 36, 24, 60, 42, 40, 56, 30, 72, 32, 48, 54, 48, 38, 60, 56, 90, 42, 96, 44, 84, 78, 72, 48, 124, 72, 98, 54, 120, 72, 120, 80, 90, 60, 168, 62, 96, 104, 84, 144, 68, 126, 96, 144

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = sigma(A028983(n)) = A000203(A028983(n)). - Jaroslav Krizek, Oct 06 2009

MATHEMATICA

Select[DivisorSigma[1, Range[100]], EvenQ] (* Harvey P. Dale, Jun 18 2017 *)

PROG

(PARI) list(lim) = select(x -> !(x % 2), vector(lim, i, sigma(i))); \\ Amiram Eldar, Dec 26 2024

CROSSREFS

Cf. A000203, A028983, A152677, A152679.

Sequence in context: A274298 A270835 A272063 * A110758 A189765 A074162

Adjacent sequences: A152675 A152676 A152677 * A152679 A152680 A152681

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, Dec 10 2008

STATUS

approved