A025638 Exponent of 2 (value of i) in n-th number of form 2^i*9^j.

0, 1, 2, 3, 0, 4, 1, 5, 2, 6, 3, 0, 7, 4, 1, 8, 5, 2, 9, 6, 3, 0, 10, 7, 4, 1, 11, 8, 5, 2, 12, 9, 6, 3, 0, 13, 10, 7, 4, 1, 14, 11, 8, 5, 2, 15, 12, 9, 6, 3, 0, 16, 13, 10, 7, 4, 1, 17, 14, 11, 8, 5, 2, 18, 15, 12, 9, 6, 3, 19, 0, 16, 13, 10, 7, 4, 20, 1, 17, 14, 11, 8, 5, 21, 2, 18, 15, 12, 9, 6, 22

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A025611.

Programs

Maple

N:= 10^8: # for 2^i*9^j <= N
B:= sort([seq(seq(2^i*9^j,i=0..ilog2(N/9^j)),j=0..floor(log[9](N)))]):
map(padic:-ordp,B,2); # Robert Israel, Jun 08 2018