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A277543 a(n) = n/5^m mod 5, where 5^m is the greatest power of 5 that divides n. 6

%I #14 Oct 26 2016 15:23:57

%S 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,

%T 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,

%U 4,4,1,2,3,4,3,1,2,3,4,1,1,2,3,4,2,1

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

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

%H Clark Kimberling, <a href="/A277543/b277543.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A132739(n) mod 5 = A010874(A132739(n)). - _Michel Marcus_, Oct 20 2016

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

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

%o (PARI) a(n) = n/5^valuation(n, 5) % 5; \\ _Michel Marcus_, Oct 20 2016

%Y Cf. A007091, A010874, A132739.

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

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Oct 19 2016

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Last modified May 1 20:04 EDT 2024. Contains 372176 sequences. (Running on oeis4.)