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