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 A359016 #7 Feb 16 2025 08:34:04 %S A359016 4,7,9,16,31,48,28,160,54,512,128,512,946,4224,512,10240,11566,4095, %T A359016 1024,65535,94794,180224,22796,262143,1048575,7077888,1339848 %N A359016 a(n) is the index of the smallest n-gonal pyramidal number with exactly n prime factors (counted with multiplicity). %H A359016 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimeFactor.html">Prime Factor</a> %H A359016 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PyramidalNumber.html">Pyramidal Number</a> %o A359016 (PARI) a(n) = if(n<3, return()); for(k=1, oo, my(t=(k*(k+1)*((n-2)*k + (5-n)))\6); if(bigomega(t) == n, return(k))); \\ _Daniel Suteu_, Dec 12 2022 %Y A359016 Cf. A358865, A359015. %K A359016 nonn,more %O A359016 3,1 %A A359016 _Ilya Gutkovskiy_, Dec 12 2022 %E A359016 a(27)-a(29) from _Daniel Suteu_, Dec 12 2022