A126207 Number of 5's in decimal expansion of 5^n.

0, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 3, 3, 3, 2, 2, 1, 2, 2, 3, 3, 3, 2, 2, 4, 2, 3, 5, 3, 2, 3, 3, 2, 5, 4, 3, 5, 2, 6, 5, 1, 2, 1, 6, 5, 6, 4, 4, 3, 2, 4, 9, 9, 9, 4, 4, 2, 5, 2, 4, 5, 5, 7, 8, 6, 5, 5, 5, 7, 6, 11, 7, 7, 5, 5, 6, 7, 6, 8, 8, 10, 5, 6, 7, 8, 9, 4, 10, 7, 4, 8, 10, 9, 6, 5, 6, 10, 6

Offset

0,7

Links

Table of n, a(n) for n=0..100.

Maple

P:=proc(n) local i, k, x, y, w, cont; y:=5; k:=y; for i from 0 by 1 to n do x:=y^i; cont:=0; while x>0 do w:=x-trunc(x/10)*10; if w=k then cont:=cont+1; fi; x:=trunc(x/10); od; print(cont); od; end: P(100);

Crossrefs

Cf. A065710, A126205, A126206, A126208, A126209, A126210, A126211.

Sequence in context: A278161 A069258 A273134 * A276711 A351451 A191322

Adjacent sequences: A126204 A126205 A126206 * A126208 A126209 A126210

Keyword

nonn,base

Author

Paolo P. Lava and Giorgio Balzarotti, Dec 20 2006

Status

approved