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 A177355 #12 Jan 22 2025 06:35:26 %S A177355 3,1,3,4,14,10,26,22,22,61,38,59,97,77,70,82,156 %N A177355 The number of positive integers m for which the exponents of prime(n) and prime(n+1) in the prime power factorization of m! are both powers of 3. %H A177355 Vladimir Shevelev, <a href="https://eudml.org/doc/277854">Compact integers and factorials</a>, Acta Arithmetica 126 (2007), no. 3, 195-236. %F A177355 All such m belong to interval [q, 2*(-1+q^2*(log(2)/(2*log(q)-1)+1))), where q=p_(n+1). %e A177355 If n=1, then 3<=m<2*(-1+9*(log(2)/(2*log(3)-1)+1))=26.4... In interval [3,26.3) we find only 3 numbers m=3,4,5 with required property. Therefore, a(1)=3. %Y A177355 Cf. A000142, A177349, A177378, A177436, A177458, A177459, A177498. %K A177355 nonn,more %O A177355 1,1 %A A177355 _Vladimir Shevelev_, May 07 2010