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 A338882 Product of the nonzero digits of (n written in base 9). 2

%I

%S 1,1,2,3,4,5,6,7,8,1,1,2,3,4,5,6,7,8,2,2,4,6,8,10,12,14,16,3,3,6,9,12,

%T 15,18,21,24,4,4,8,12,16,20,24,28,32,5,5,10,15,20,25,30,35,40,6,6,12,

%U 18,24,30,36,42,48,7,7,14,21,28,35,42,49,56,8,8,16,24,32,40,48,56,64

%N Product of the nonzero digits of (n written in base 9).

%F G.f. A(x) satisfies: A(x) = (1 + x + 2*x^2 + 3*x^3 + 4*x^4 + 5*x^5 + 6*x^6 + 7*x^7 + 8*x^8) * A(x^9).

%t Table[Times @@ DeleteCases[IntegerDigits[n, 9], 0], {n, 0, 80}]

%t nmax = 80; A[_] = 1; Do[A[x_] = (1 + x + 2 x^2 + 3 x^3 + 4 x^4 + 5 x^5 + 6 x^6 + 7 x^7 + 8 x^8) A[x^9] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]

%o (PARI) a(n) = vecprod(select(x->x, digits(n, 9))); \\ _Michel Marcus_, Nov 14 2020

%Y Product of the nonzero digits of (n written in base k): A000012 (k = 2), A117592 (k = 3), A338854 (k = 4), A338803 (k = 5), A338863 (k = 6), A338880 (k = 7), A338881 (k = 8), this sequence (k = 9), A051801 (k = 10).

%Y Cf. A007095, A309788.

%K nonn,base

%O 0,3

%A _Ilya Gutkovskiy_, Nov 13 2020

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Last modified August 3 19:49 EDT 2021. Contains 346441 sequences. (Running on oeis4.)