A081467 a(n) = smallest (n+k) such that n divides the sum {(n+1)+ (n+2) + ... (n+k)} or n divides kn + k(k+1)/2.

2, 5, 5, 11, 9, 9, 13, 23, 17, 14, 21, 20, 25, 21, 20, 47, 33, 26, 37, 35, 27, 33, 45, 39, 49, 38, 53, 35, 57, 45, 61, 95, 44, 50, 49, 44, 73, 57, 51, 55, 81, 62, 85, 76, 54, 69, 93, 80, 97, 74, 68, 91, 105, 81, 65, 104, 75, 86, 117, 75

Offset

1,1

Links

Table of n, a(n) for n=1..60.

Example

a(4) = 11 as 4 divides 5+6+7+8+9+10+11 and not a smaller sum.

Crossrefs

Cf. A081468, A081469, A081470, A081471, A081472.

Sequence in context: A132295 A086651 A074495 * A194119 A084721 A273041

Adjacent sequences: A081464 A081465 A081466 * A081468 A081469 A081470

Keyword

nonn

Author

Amarnath Murthy, Mar 23 2003

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003

Status

approved