A248137 Least positive integer m such that m + n divides M(m) + M(n), where M(.) is given by A001006.

1, 1, 244, 1, 23, 4, 1, 1, 3494, 1, 68058, 4, 20, 18, 35, 1, 4, 14, 32, 13, 21, 1, 5, 22, 172, 7, 8, 1, 1, 28, 14, 19, 2, 178, 15, 227, 2, 6, 109, 1, 22, 122, 47, 22, 126, 1, 43, 60, 41, 18, 24, 1, 13, 23, 21, 24, 126, 1, 152, 6

Offset

1,3

Comments

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

Links

Zhi-Wei Sun, Table of n, a(n) for n = 1..2187

Example

a(5) = 23 since 5 + 23 = 28 divides M(5) + M(23) = 21 + 1129760415 = 1129760436 = 28*40348587.

Mathematica

M[n_]:=Sum[Binomial[n, 2k]Binomial[2k, k]/(k+1), {k, 0, n/2}]
Do[m=1; Label[aa]; If[Mod[M[m]+M[n], m+n]==0, Print[n, " ", m]; Goto[bb]]; m=m+1; Goto[aa]; Label[bb]; Continue, {n, 1, 60}]

Crossrefs

Cf. A001006, A247824, A247937, A247940, A248124, A248125, A248133, A248136, A248139, A248142.

Sequence in context: A164657 A151638 A352033 * A243774 A051002 A044987

Adjacent sequences: A248134 A248135 A248136 * A248138 A248139 A248140

Keyword

nonn

Author

Zhi-Wei Sun, Oct 02 2014

Status

approved