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 A338882 Product of the nonzero digits of (n written in base 9). 2
 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, 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, 18, 24, 30, 36, 42, 48, 7, 7, 14, 21, 28, 35, 42, 49, 56, 8, 8, 16, 24, 32, 40, 48, 56, 64 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS FORMULA 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). MATHEMATICA Table[Times @@ DeleteCases[IntegerDigits[n, 9], 0], {n, 0, 80}] 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] PROG (PARI) a(n) = vecprod(select(x->x, digits(n, 9))); \\ Michel Marcus, Nov 14 2020 CROSSREFS 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). Cf. A007095, A309788. Sequence in context: A255829 A277547 A190598 * A053844 A010887 A101412 Adjacent sequences:  A338879 A338880 A338881 * A338883 A338884 A338885 KEYWORD nonn,base AUTHOR Ilya Gutkovskiy, Nov 13 2020 STATUS approved

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Last modified June 14 08:31 EDT 2021. Contains 345018 sequences. (Running on oeis4.)