A022333 Exponent of 5 (value of j) in n-th number of form 2^i*5^j.

0, 0, 0, 1, 0, 1, 0, 1, 2, 0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 4, 1, 2, 3, 0, 4, 1, 2, 3, 0, 4, 1, 5, 2, 3, 0, 4, 1, 5, 2, 3, 0, 4, 1, 5, 2, 6, 3, 0, 4, 1, 5, 2, 6, 3, 0, 4, 1, 5, 2, 6, 3, 0, 7, 4, 1, 5, 2, 6, 3, 0, 7, 4, 1, 5, 2, 6, 3, 0, 7, 4, 1, 8, 5, 2, 6, 3, 0, 7, 4, 1, 8, 5, 2, 6, 3, 0, 7, 4, 1, 8, 5, 2

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A003592, A022332, A112765.

Programs

Maple

A022333 := proc(n)
    A112765(A003592(n)) ;
end proc:
seq(A022333(n),n=1..20) ; # R. J. Mathar, Aug 04 2016

Mathematica

s = {}; m = 12; Do[n = 5^k; While[n <= 5^m, AppendTo[s, n]; n *= 2], {k, 0, m}]; IntegerExponent[#, 5] & /@ Union[s]

PARI

lista(nn) = {vec = vector(nn, i , i); subset = select(n->(n/(2^valuation(n,2)*5^valuation(n,5)) == 1), vec); for (i = 1, #subset, print1(valuation(subset[i], 5), ", "););} \\ Michel Marcus, Oct 01 2013

Formula

a(n) = A112765(A003592(n)). - Amiram Eldar, Feb 07 2020