A248136 Least positive integer m such that m + n divides D(m) + D(n), where D(.) is given by A001850.

1, 20, 3, 6, 1, 4, 200, 299, 5, 29, 4, 119, 5, 61, 3, 3, 6, 64, 31, 2, 21, 35, 6, 2974, 17, 1052, 27, 109, 10, 4, 3, 50, 65, 177, 22, 29, 5, 25, 15, 29, 29, 584, 83, 163, 9, 152, 19, 19, 29, 32, 15, 35, 4, 25, 239, 1122, 185, 76, 35, 97

Offset

1,2

Comments

Conjecture: a(n) exists for any n > 0.

Links

Zhi-Wei Sun, Table of n, a(n) for n = 1..10000

Example

a(2) = 20 since 2 + 20 = 22 divides D(2) + D(20) = 13 + 260543813797441 = 260543813797454 = 22*11842900627157.

Mathematica

d[n_]:=Sum[Binomial[n, k]Binomial[n+k, k], {k, 0, n}]
Do[m=1; Label[aa]; If[Mod[d[m]+d[n], m+n]==0, Print[n, " ", m]; Goto[bb]]; m=m+1; Goto[aa]; Label[bb]; Continue, {n, 1, 60}]

Crossrefs

Cf. A001850, A247824, A247937, A247940, A248124, A248125, A248133, A248137, A248139, A248142.

Sequence in context: A195600 A118295 A070645 * A040392 A317320 A327701

Adjacent sequences: A248133 A248134 A248135 * A248137 A248138 A248139

Keyword

nonn

Author

Zhi-Wei Sun, Oct 02 2014

Status

approved