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A309958
Product of digits of (n written in base 7).
4
0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 2, 4, 6, 8, 10, 12, 0, 3, 6, 9, 12, 15, 18, 0, 4, 8, 12, 16, 20, 24, 0, 5, 10, 15, 20, 25, 30, 0, 6, 12, 18, 24, 30, 36, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 0, 2, 4, 6, 8, 10, 12, 0, 3, 6, 9, 12, 15, 18, 0, 4, 8, 12, 16, 20, 24, 0, 5, 10, 15, 20, 25, 30, 0, 6, 12, 18, 24, 30, 36, 0, 0, 0
OFFSET
0,3
LINKS
FORMULA
G.f. A(x) satisfies: A(x) = x * (1 + 2*x + 3*x^2 + 4*x^3 + 5*x^4 + 6*x^5) * (1 + A(x^7)).
MATHEMATICA
Table[Times @@ IntegerDigits[n, 7], {n, 0, 100}]
PROG
(Magma) [0] cat [&*Intseq(n, 7):n in [1..100]]; // Marius A. Burtea, Aug 25 2019
(PARI) a(n) = my(v=vecprod(digits(n, 7))); n>0 && return(v) \\ Felix Fröhlich, Sep 09 2019
CROSSREFS
Product of digits of (n written in base k): A309953 (k = 3), A309954 (k = 4), A309956 (k = 5), A309957 (k = 6), this sequence (k = 7), A309959 (k = 8), A309788 (k = 9), A007954 (k = 10).
Sequence in context: A347729 A031007 A010876 * A055400 A367842 A257847
KEYWORD
nonn,base
AUTHOR
Ilya Gutkovskiy, Aug 24 2019
STATUS
approved