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 A358929 #10 Feb 16 2025 08:34:04
%S A358929 1,19,4,316,136,760,64,4960,22144,103360,27136,5492224,1186816,
%T A358929 41414656,271212544,559980544,1334788096,12943360,7032930304,
%U A358929 527049293824,158186536960,1096295120896,7871801589760,154690378792960,13071965224960,56262393856,964655941943296
%N A358929 a(n) is the smallest centered triangular number with exactly n prime factors (counted with multiplicity).
%H A358929 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredTriangularNumber.html">Centered Triangular Number</a>
%H A358929 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimeFactor.html">Prime Factor</a>
%e A358929 a(4) = 136, because 136 is a centered triangular number with 4 prime factors (counted with multiplicity) {2, 2, 2, 17} and this is the smallest such number.
%t A358929 c[k_] := (3*k^2 + 3*k + 2)/2; a[n_] := Module[{k = 0, ck}, While[PrimeOmega[ck = c[k]] != n, k++]; ck]; Array[a, 18, 0] (* _Amiram Eldar_, Dec 09 2022 *)
%o A358929 (PARI) a(n) = if(n==0, return(1)); for(k=1, oo, my(t=3*k*(k+1)/2 + 1); if(bigomega(t) == n, return(t))); \\ _Daniel Suteu_, Dec 10 2022
%Y A358929 Cf. A001222, A005448, A075088, A358926, A358927, A358928.
%K A358929 nonn
%O A358929 0,2
%A A358929 _Ilya Gutkovskiy_, Dec 06 2022
%E A358929 a(22)-a(26) from _Daniel Suteu_, Dec 10 2022