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 A147849 #7 Dec 01 2021 03:54:35
%S A147849 3,6,6,10,15,15,21,21,28,36,36,45,45,45,55,55,66,66,78,78,78,91,91,91,
%T A147849 105,105,105,120,120,120,136,136,153,153,153,153,171,171,171,190,190,
%U A147849 190,210,210,210,210,231,231,231,231,253,253,253,253,276,276,276,276
%N A147849 a(n) is the smallest triangular number > n-th prime.
%t A147849 a1 = Reap[Do[p = Prime[m]; Do[t = n (n + 1)/2; If[t > p, Sow[t]; Break[]], {n, 200}], {m, 100}]][[2, 1]]
%Y A147849 Cf. A097050 (smallest prime > n-th triangular number).
%Y A147849 Cf. A000040, A000217.
%K A147849 nonn
%O A147849 1,1
%A A147849 _Zak Seidov_, Nov 15 2008