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Exponent of 5 (value of k) in n-th number of the form 2^i*3^j*5^k.
7

%I #7 Feb 07 2020 08:22:04

%S 0,0,0,0,1,0,0,0,1,0,1,0,0,1,0,2,0,1,0,0,1,1,0,2,0,1,0,0,2,1,0,1,0,2,

%T 0,1,3,0,1,0,2,1,0,1,0,2,0,2,1,0,3,0,1,0,2,1,0,1,3,0,2,1,0,2,1,0,3,0,

%U 1,0,2,4,1,0,2,1,0,3,0,2,1,0,2,1,0,3,0,1,3,0,2,1,4,1,0,2,1,0,3,0,2,1,0,2,4

%N Exponent of 5 (value of k) in n-th number of the form 2^i*3^j*5^k.

%H Amiram Eldar, <a href="/A112762/b112762.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A112765(A051037(n));

%F a(n) = A112759(n) - A112760(n) - A112761(n).

%t IntegerExponent[#, 5] & /@ Select[Range[3000], Last @ Map[First, FactorInteger[#]] <= 5 &] (* _Amiram Eldar_, Feb 07 2020 *)

%Y Cf. A022337, A051037, A112765, A112760, A112761.

%K nonn

%O 1,16

%A _Reinhard Zumkeller_, Sep 18 2005