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 A377934 #11 Nov 24 2024 20:35:01
%S A377934 1,2,7,17,38,75,152,306,616,1260,2598,5401,11307,23798,50316,106776,
%T A377934 227236,484737,1036002,2217529,4752349,10194727,21887147,47020054,
%U A377934 101065880,217325603,467484989,1005881993,2164843035,4660016778,10032642455,21602193212,46518438071
%N A377934 a(n) is the number of perfect powers m^k with k>=3 (A076467) <= 10^n.
%H A377934 Chai Wah Wu, <a href="/A377934/b377934.txt">Table of n, a(n) for n = 0..2999</a>
%F A377934 a(n) = 10^n - Sum_{k=1..floor(log2(10^n))} mu(k)*(floor(10^(n/k))+floor(10^(n/(2k)))-2). - _Chai Wah Wu_, Nov 24 2024
%e A377934 a(0) = 1: 1^k with any k>2 (<= 10^0);
%e A377934 a(1) = 2: 1 and 2^3 (<=10^1);
%e A377934 a(2) = 7: 2 powers <= 10 and 16, 27, 32, 64, 81 (<=10^2).
%o A377934 (Python)
%o A377934 from math import gcd
%o A377934 from sympy import integer_nthroot, mobius
%o A377934 def A377934(n): return int(integer_nthroot(10**(n//(a:=gcd(n,4))),4//a)[0]-sum(mobius(k)*(integer_nthroot(10**(n//(b:=gcd(n,k))),k//b)[0]+integer_nthroot(10**(n//(c:=gcd(n,d:=k<<1))),d//c)[0]-2) for k in range(3,(10**n).bit_length()))) # _Chai Wah Wu_, Nov 24 2024
%Y A377934 Cf. A070428, A076467, A378168.
%K A377934 nonn
%O A377934 0,2
%A A377934 _Hugo Pfoertner_, Nov 24 2024
%E A377934 a(28) onwards from _Chai Wah Wu_, Nov 24 2024