A185961 - OEIS

A185961

Let d_1=1 < d_2 < d_3 < ... be the divisors of n; sequence lists positive numbers n such that for some k, n = 2(d_1 + ... + d_k).

2, 6, 12, 28, 40, 48, 224, 234, 496, 960, 8128, 47616, 174592, 10371840, 15037440, 28090368, 33550336, 134209536, 207516672, 492101632, 1150402560, 8589869056, 59205411720, 137438691328

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

OFFSET

1,1

REFERENCES

Arie Groeneveld, Posting to Sequence Fans Mailing List, Feb 06, 2011

LINKS

Table of n, a(n) for n=1..24.

PROG

(PARI) forstep(n=2, 33550336, 2, d=divisors(n); s=0; for(j=1, numdiv(n), s=s+2*d[j]; if(s>=n, if(s==n, print1(n ", ")); next(2)))) \\ Donovan Johnson, Jan 24 2014

CROSSREFS

Supersequence of A000396.

Cf. A064510, A185584, A185960.

Sequence in context: A188476 A155583 A140853 * A290674 A290419 A159553

Adjacent sequences: A185958 A185959 A185960 * A185962 A185963 A185964

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Feb 07 2011

EXTENSIONS

a(14)-a(22) from Donovan Johnson, Feb 10 2011

a(23)-a(24) from Donovan Johnson, Jan 24 2014

STATUS

approved