|
| |
|
|
A072542
|
|
a(n) = the least positive integer k such that sigma(k) > sigma(1) + ... + sigma(n).
|
|
0
| |
|
|
2, 4, 6, 10, 12, 18, 20, 24, 30, 36, 48, 60, 60, 60, 72, 84, 96, 108, 120, 120, 144, 168, 168, 180, 180, 210, 240, 240, 240, 288, 288, 300, 336, 336, 360, 360, 360, 420, 420, 420, 480, 480, 504, 540, 600, 600, 600, 660, 660, 720, 720, 720, 720, 840, 840, 840
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
EXAMPLE
| sigma(1) + ... + sigma(4) = 15 and k = 10 is the least positive integer such that sigma(k) > 15. Hence a(4) = 10.
|
|
|
MATHEMATICA
| s = 0; a = {}; For[i = 1, i <= 100, i++, s = s + DivisorSigma[1, i]; k = 1; While[DivisorSigma[1, k] <= s, k = k + 1]; a = Append[a, k]]; a
|
|
|
CROSSREFS
| Sequence in context: A033098 A033868 A045954 * A167856 A162578 A152919
Adjacent sequences: A072539 A072540 A072541 * A072543 A072544 A072545
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 08 2002
|
| |
|
|
