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 A278139 #6 Nov 27 2016 22:02:25
%S A278139 2,3,13,41,107,227,503,881,1409,2039,2819,3947,5273,6869,8699,11549,
%T A278139 15377,19937,24593,30809,38069,47939,58379,69257,82787,98897,115733,
%U A278139 133499,152027,172127,192833,218711,247391,279269,315047,355517,399473,444623
%N A278139 Primes, starting with a(1)=2, whose successive differences are increasing triangular numbers.
%t A278139 lst={1};p[1]=2;p[n_]:=p[n]=Module[{i=Last[lst]+1},
%t A278139 While[!PrimeQ[p[n-1]+i*(i-1)/2],i++];AppendTo[lst,i];p[n-1]+i*(i-1)/2];
%t A278139 p/@Range[50]
%Y A278139 Cf. A088173, A275030.
%K A278139 easy,nonn
%O A278139 1,1
%A A278139 _Ivan N. Ianakiev_, Nov 13 2016