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A015999 a(n) = (tau(n^5) + 4)/5. 15

%I #28 Mar 13 2021 10:04:13

%S 1,2,2,3,2,8,2,4,3,8,2,14,2,8,8,5,2,14,2,14,8,8,2,20,3,8,4,14,2,44,2,

%T 6,8,8,8,25,2,8,8,20,2,44,2,14,14,8,2,26,3,14,8,14,2,20,8,20,8,8,2,80,

%U 2,8,14,7,8,44,2,14,8,44,2,36,2,8,14,14,8,44,2,26,5,8,2,80,8,8

%N a(n) = (tau(n^5) + 4)/5.

%H Antti Karttunen, <a href="/A015999/b015999.txt">Table of n, a(n) for n = 1..10000</a>

%p with(numtheory): A015999:=n->(tau(n^5)+4)/5: seq(A015999(n), n=1..80); # _Wesley Ivan Hurt_, Apr 10 2015

%t (DivisorSigma[0, Range[80]^5]+4)/5 (* _Wesley Ivan Hurt_, Apr 10 2015 *)

%o (PARI)

%o A015999(n) = (numdiv(n^5)+4)/5;

%o for(n=1, 10000, write("b015999.txt", n, " ", A015999(n)));

%o \\ _Antti Karttunen_, Jan 17 2017

%o (Python)

%o from sympy import divisor_count

%o def a(n): return (divisor_count(n**5) + 4)//5

%o print([a(n) for n in range(1, 101)]) # _Indranil Ghosh_, Apr 14 2017

%Y Cf. A000005, A018892, A015995, A015996, A016001, A016002, A016003, A016005, A016006, A016007, A016008, A016012.

%K nonn,easy

%O 1,2

%A _Robert G. Wilson v_

%E Definition corrected by _Vladeta Jovovic_, Sep 03 2005

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Last modified March 28 15:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)