This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A367932 #12 Mar 28 2025 07:15:18 %S A367932 1,4,9,2,25,36,49,1,3,100,121,18,169,196,225,2,289,12,361,50,441,484, %T A367932 529,9,5,676,1,98,841,900,961,1,1089,1156,1225,6,1369,1444,1521,25, %U A367932 1681,1764,1849,242,75,2116,2209,18,7,20,2601,338,2809,4,3025,49,3249,3364 %N A367932 a(n) is the smallest number k such that k*n is an exponentially evil number (A262675). %C A367932 First differs from A365298 at n = 64. %H A367932 Amiram Eldar, <a href="/A367932/b367932.txt">Table of n, a(n) for n = 1..10000</a> %F A367932 Multiplicative with a(p^e) = p^s(e), s(e) = min{k >= e, k is evil} - e. %F A367932 a(n) = A367934(n)/n. %F A367932 a(n) >= 1, with equality if and only if n is an exponentially evil number (A262675). %F A367932 Sum_{k=1..n} a(k) ~ c * n^3 / 3, where c = Product_{p prime} f(1/p) = 0.623746285..., where f(x) = (1-x) * (1 + Sum_{k>=1} x^(3*k-s(k))), and s(k) is defined above. %t A367932 f[p_, e_] := Module[{k = e}, While[! EvenQ[DigitCount[k, 2 ,1]], k++]; p^(k-e)]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] %o A367932 (PARI) s(e) = {my(k = e); while(hammingweight(k)%2, k++); k - e; }; %o A367932 a(n) = {my(f = factor(n)); prod(i = 1, #f~, f[i, 1]^s(f[i, 2])); } %Y A367932 Cf. A001969, A262675, A367934. %Y A367932 Similar sequences: A365298, A365685, A367931. %K A367932 nonn,easy,mult,base %O A367932 1,2 %A A367932 _Amiram Eldar_, Dec 05 2023