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 A196421 #36 Sep 01 2022 20:02:26
%S A196421 2,9,30,70,165,273,476,684,1035,1595,2046,2886,3731,4515,5640,7208,
%T A196421 9027,10431,12730,14910,16863,19987,22908,26700,31525,35451,38934,
%U A196421 43442,47415,52545,62992,69168,76857,82705,93870,100566,110371,120783,130260,141860
%N A196421 a(n) = prime(n)*T(n), where T = A000217.
%C A196421 This sequence is mentioned in A077320. - _Omar E. Pol_, Mar 12 2012
%H A196421 Harvey P. Dale, <a href="/A196421/b196421.txt">Table of n, a(n) for n = 1..10000</a>
%F A196421 a(n) ~ 0.5 n^3 log n. - _Charles R Greathouse IV_, Nov 22 2011
%F A196421 a(n) = A000040(n)*A000217(n). - _Omar E. Pol_, Mar 12 2012
%e A196421 The 4th prime is 7, the 4th triangular number is 10, therefore a(4) = 7*10 = 70.
%t A196421 With[{nn=60},Prime[Range[nn]]Accumulate[Range[nn]]]
%o A196421 (PARI) a(n)=prime(n)*binomial(n+1,2) \\ _Charles R Greathouse IV_, Nov 22 2011
%o A196421 (Python)
%o A196421 from sympy import prime
%o A196421 def a(n): return prime(n) * n*(n+1)//2
%o A196421 print([a(n) for n in range(1, 41)]) # _Michael S. Branicky_, Sep 01 2022
%Y A196421 Cf. A000040, A000217.
%Y A196421 Row sums of triangle A077320. - _Omar E. Pol_, Mar 12 2012
%Y A196421 Subsequence of A085783. - _Michel Marcus_, May 15 2018
%K A196421 nonn
%O A196421 1,1
%A A196421 _Harvey P. Dale_, Oct 15 2011