A277543 a(n) = n/5^m mod 5, where 5^m is the greatest power of 5 that divides n.

1, 2, 3, 4, 1, 1, 2, 3, 4, 2, 1, 2, 3, 4, 3, 1, 2, 3, 4, 4, 1, 2, 3, 4, 1, 1, 2, 3, 4, 1, 1, 2, 3, 4, 2, 1, 2, 3, 4, 3, 1, 2, 3, 4, 4, 1, 2, 3, 4, 2, 1, 2, 3, 4, 1, 1, 2, 3, 4, 2, 1, 2, 3, 4, 3, 1, 2, 3, 4, 4, 1, 2, 3, 4, 3, 1, 2, 3, 4, 1, 1, 2, 3, 4, 2, 1

Offset

1,2

Comments

a(n) is the rightmost nonzero digit in the base 5 expansion of n (A007091).

Links

Clark Kimberling, Table of n, a(n) for n = 1..10000

Formula

a(n) = A132739(n) mod 5 = A010874(A132739(n)). - Michel Marcus, Oct 20 2016

Example

a(20) = (20/5 mod 5) = 4.

Mathematica

Table[Mod[n/5^IntegerExponent[n, 5], 5], {n, 1, 160}]

Prog

(PARI) a(n) = n/5^valuation(n, 5) % 5; \\ Michel Marcus, Oct 20 2016

Crossrefs

Cf. A007091, A010874, A132739.

Cf. A277550, A277551, A277555, A277548 (positions of 1, 2, 3 and 4 in this sequence).

Sequence in context: A350351 A138297 A139458 * A190594 A338803 A104412

Adjacent sequences: A277540 A277541 A277542 * A277544 A277545 A277546

Keyword

nonn,easy

Author

Clark Kimberling, Oct 19 2016

Status

approved