A358991 - OEIS

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A358991

a(n) is the number of zero digits in the product of the first n odd numbers not divisible by 5.

0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 2, 1, 0, 2, 1, 1, 2, 2, 3, 2, 2, 2, 3, 2, 4, 5, 2, 4, 1, 3, 4, 5, 6, 9, 5, 4, 6, 4, 7, 7, 10, 5, 7, 10, 8, 9, 8, 4, 7, 4, 15, 9, 4, 7, 12, 9, 8, 14, 12, 5, 14, 12, 6, 11, 10, 14, 17, 17, 11, 19, 11, 15, 19, 15, 13, 14, 11, 19

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OFFSET

0,14

LINKS

Table of n, a(n) for n=0..80.

FORMULA

a(n) = A055641(A356990(n)).

MATHEMATICA

Table[Count[IntegerDigits[Product[2i+2Floor[(i-3)/4]+1, {i, n}]], 0], {n, 0, 80}]

CROSSREFS

Cf. A045572, A055641, A356859, A358990.

Cf. A358992 (number of digits), A358993 (number of nonzero digits).