A066974 Integers of the form (1/m)*sum(i=1,m,binomial(2i,i)).

2, 4, 70, 2197, 86944, 305045, 184940110, 480921672850, 1390639119568762, 13871716673121190349872, 46286334476836197400150816, 158305268738561655232891129492, 552015921314537446560239006496196

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Mathematica

Select[Table[Sum[Binomial[2i, i]/m, {i, m}], {m, 60}], IntegerQ] (* Harvey P. Dale, Dec 23 2014 *)

Crossrefs

Sequence in context: A301818 A054920 A062061 * A270583 A018373 A292414

Adjacent sequences: A066971 A066972 A066973 * A066975 A066976 A066977

Keyword

nonn

Author

Benoit Cloitre, Jan 26 2002

Status

approved