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 A260236 #7 Aug 10 2021 14:14:11 %S A260236 2,2,3,3,3,2,5,3,3,3,4,3,5,3,5,3,5,2,5,3,3,4,5,4,4,4,5,3,4,2,8,4,3,4, %T A260236 5,2,5,4,5,5,4,3,5,4,4,3,7,3,6,3,4,4,5,3,6,3,4,4,6,3,4,6,7,4,4,3,7,3, %U A260236 4,3,7,3,5,4,4,5,5,2,7,6,3,4,5,4,5,3 %N A260236 Number of prime factors, with multiplicity, of the n-th hexagonal number (A000384). %H A260236 Colin Barker, <a href="/A260236/b260236.txt">Table of n, a(n) for n = 2..1000</a> %F A260236 a(n) = A001222(A000384(n)). %e A260236 a(4) = 3 because A000384(4) = 28 = 2^2 * 7. %t A260236 Rest[PrimeOmega[PolygonalNumber[6,Range[90]]]] (* _Harvey P. Dale_, Aug 10 2021 *) %o A260236 (PARI) %o A260236 pg(m, n) = (n^2*(m-2)-n*(m-4))/2 \\ n-th m-gonal number %o A260236 a(n) = bigomega(pg(6, n)) %Y A260236 Cf. A000384, A001222, A260233, A260234, A260235. %K A260236 nonn %O A260236 2,1 %A A260236 _Colin Barker_, Jul 20 2015