A152679 Even members of A000203, divided by 2.

2, 3, 6, 4, 9, 6, 14, 7, 12, 12, 9, 10, 21, 16, 18, 12, 30, 21, 20, 28, 15, 36, 16, 24, 27, 24, 19, 30, 28, 45, 21, 48, 22, 42, 39, 36, 24, 62, 36, 49, 27, 60, 36, 60, 40, 45, 30, 84, 31, 48, 52, 42, 72, 34, 63, 48, 72

Offset

1,1

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Formula

a(n) = A152678(n)/2.

Mathematica

Select[Table[DivisorSigma[1, n]/2, {n, 1, 70}], IntegerQ](* Ivan Neretin, May 09 2015 *)

Prog

(PARI) list(lim) = select(x -> denominator(x) == 1, vector(lim, i, sigma(i)/2)); \\ Amiram Eldar, Dec 26 2024

Crossrefs

Cf. A000203, A152677, A152678.

Sequence in context: A125147 A103864 A268712 * A232561 A348395 A320123

Adjacent sequences: A152676 A152677 A152678 * A152680 A152681 A152682

Keyword

easy,nonn

Author

Omar E. Pol, Dec 10 2008

Status

approved