A358993 a(n) is the number of nonzero digits in the product of the first n odd numbers not divisible by 5.

1, 1, 1, 2, 3, 3, 4, 6, 7, 9, 10, 12, 12, 13, 15, 18, 17, 20, 21, 22, 24, 25, 27, 29, 31, 32, 34, 34, 35, 40, 40, 45, 45, 45, 46, 47, 46, 52, 55, 55, 59, 58, 60, 59, 66, 66, 65, 69, 70, 74, 80, 79, 84, 75, 83, 90, 89, 87, 92, 95, 91, 95, 104, 98, 102, 110, 107

Offset

0,4

Links

Table of n, a(n) for n=0..66.

Formula

a(n) = A055640(A358990(n)).

Mathematica

Table[Length[Select[IntegerDigits[Product[2i+2Floor[(i-3)/4]+1, {i, n}]], Positive]], {n, 0, 66}]

Crossrefs

Cf. A045572, A055640, A356861, A358990.

Cf. A358991 (number of zero digits), A358992 (number of digits).

Sequence in context: A036018 A123552 A071610 * A198726 A117275 A327725

Adjacent sequences: A358990 A358991 A358992 * A358994 A358995 A358996

Keyword

nonn,base

Author

Stefano Spezia, Dec 09 2022

Status

approved