A086992 Product of nonzero digits in n-th row of Pascal's triangle.

1, 1, 2, 9, 96, 25, 1800, 44100, 103219200, 3869835264, 128000, 104976000000, 3071875232563200, 7050692013745766400, 626913312768, 332150625000000000000, 1292730125539029811200

Offset

1,3

Links

Table of n, a(n) for n=1..17.

Example

a(6) = 25 because the digits in the 5th row of Pascal's triangle are 1,5,(1,0),(1,0),5,1, the product of the nonzero terms is 25. - Richard M. Green, Feb 12 2014

Mathematica

A086992[n_]:= Times @@ DeleteCases[0]@Flatten@IntegerDigits@Table[Binomial[n, k], {k, 0, n}] (* JungHwan Min, Dec 07 2015 *)

Prog

(PARI) A051801(n)=my(v=select(k->k>1, digits(n))); prod(i=1, #v, v[i])
a(n)=prod(k=1, (n-1)\2, A051801(binomial(n, k)))^2*if(n%2, 1, A051801(binomial(n, n/2))) \\ Charles R Greathouse IV, Dec 08 2015

Crossrefs

Cf. A007318, A066600, A086993, A051801.

Sequence in context: A058156 A011837 A106343 * A354316 A345466 A115965

Adjacent sequences: A086989 A086990 A086991 * A086993 A086994 A086995

Keyword

base,easy,nonn

Author

Jason Earls, Jul 29 2003

Status

approved