|
| |
|
|
A053781
|
|
Numbers n such that n divides sum of first n composite numbers.
|
|
4
| |
|
|
1, 2, 3, 7, 11, 71, 107, 115, 139, 155, 681, 1671, 4876, 21464, 30046, 311271, 788749, 10893662, 20743270, 134568163, 163879554, 920161004, 6364787032, 21400458779, 47934932406, 56133884369, 288050185452, 536023681676, 1484061538595
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
FORMULA
| When n | A053767(n). - Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 24 2004
|
|
|
MATHEMATICA
| c = s = 0; Do[ If[ !PrimeQ[n], c++; s = s + n; If[ Mod[s, c] == 0, Print[c]]], {n, 2, 10^9}] (from Robert G. Wilson v Nov 23 2004)
|
|
|
CROSSREFS
| Cf. A002808, A073262, A073263.
Sequence in context: A106125 A175171 A073609 * A066749 A046480 A137767
Adjacent sequences: A053778 A053779 A053780 * A053782 A053783 A053784
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| G. L. Honaker, Jr. (honak3r(AT)gmail.com), Mar 29 2000
|
|
|
EXTENSIONS
| a(19), a(20), a(21) & a(22) from Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 24 2004
a(23), a(24), a(25) & a(26) from Sean A. Irvine (sairvin(AT)xtra.co.nz), Oct 01 2009
a(27)-a(29) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jul 06 2010
|
| |
|
|
