A249416 a(n) = core(Sum_{i=0,...,n} core(binomial(n,i))), where core(n) = A007913(n).

1, 2, 1, 2, 10, 2, 1, 2, 118, 19, 519, 2, 635, 370, 829, 1333, 8454, 17315, 3599, 15307, 423769, 852006, 495431, 2, 2425755, 2121070, 3192295, 1614598, 35685686, 10081687, 735961, 12902173, 216093318, 151123623, 5270424935, 39937013, 22884337, 7281379334

Offset

0,2

Links

Table of n, a(n) for n=0..37.

Mathematica

a7913[n_]:=a7913[n]=Times@@(#[[1]]^Mod[#[[2]], 2])&[Transpose[FactorInteger[n]]];
Map[a7913[Total[Map[a7913, Binomial[#, Range[0, #]]]]]&, Range[0, 50]] (* Peter J. C. Moses, Oct 28 2014 *)

Prog

(PARI) a(n) = core(sum(i=0, n, core(binomial(n, i)))); \\ Michel Marcus, Nov 13 2014

Crossrefs

Cf. A007913, A248470, A248473, A249388.

Sequence in context: A078357 A225432 A086382 * A062345 A077098 A069238

Adjacent sequences: A249413 A249414 A249415 * A249417 A249418 A249419

Keyword

nonn

Author

Vladimir Shevelev, Oct 28 2014

Extensions

More terms from Peter J. C. Moses, Oct 28 2014

Status

approved