login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

A375848
The maximum exponent in the prime factorization of the numbers whose maximum exponent in their prime factorization is an evil number (A374590).
1
0, 3, 3, 3, 5, 3, 3, 3, 6, 3, 3, 5, 3, 3, 3, 3, 3, 3, 3, 5, 3, 3, 3, 6, 3, 3, 5, 3, 5, 3, 3, 3, 3, 3, 5, 3, 3, 3, 6, 3, 3, 3, 3, 5, 3, 3, 3, 3, 3, 3, 5, 3, 3, 6, 3, 3, 3, 5, 5, 3, 3, 3, 9, 3, 3, 3, 3, 5, 3, 3, 6, 3, 3, 3, 5, 3, 3, 3, 3, 5, 3, 3, 3, 3, 3, 6, 3, 3, 6, 5, 3, 3, 3, 3, 3, 3, 3, 5, 3, 3, 6, 3, 3, 3, 5
OFFSET
1,2
FORMULA
a(n) = A051903(A374590(n)).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{k in A001969} (k * (1/zeta(k+1) - 1/zeta(k))) / d = 3.61461685523237846738..., where d = Sum_{k in A001969} (1/zeta(k+1) - 1/zeta(k)) = 0.12101890210392912747... is the asymptotic density of A374590.
MATHEMATICA
evilQ[n_] := EvenQ[DigitCount[n, 2, 1]]; s[n_] := Module[{e = Max[FactorInteger[n][[;; , 2]]]}, If[evilQ[e], e, Nothing]]; s[1] = 0; Array[s, 1000]
PROG
(PARI) lista(kmax) = {my(e); print1(0, ", "); for(k = 2, kmax, e = vecmax(factor(k)[, 2]); if(!(hammingweight(e) % 2), print1(e, ", "))); }
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
Amiram Eldar, Aug 31 2024
STATUS
approved