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 A055472 #34 Feb 19 2024 01:59:13
%S A055472 2,3,5,17,23,47,107,173,233,353,467,563,743,863,1277,1433,1487,2213,
%T A055472 2417,2777,3083,3323,4007,4373,5153,7877,8387,10733,11177,11783,13043,
%U A055472 13697,14537,15053,15227,17207,17393,17957,18917,21323,22157,23873
%N A055472 Primes of the form k(k+1)/2+2 (i.e., two more than a triangular number).
%C A055472 Equal to primes of the form (k^2+15)/8. Also equal to primes p such that 8*p-15 is a square. - _Chai Wah Wu_, Jul 14 2014
%C A055472 Primes of A152948. - _Klaus Purath_, Jan 03 2021
%H A055472 Vincenzo Librandi, <a href="/A055472/b055472.txt">Table of n, a(n) for n = 1..1000</a>
%t A055472 Select[Table[(n^2-n+4)/2,{n,3000}],PrimeQ] (* _Vincenzo Librandi_, Jul 14 2012 *)
%t A055472 Select[Accumulate[Range[0,300]]+2,PrimeQ] (* _Harvey P. Dale_, Feb 05 2019 *)
%o A055472 (Python)
%o A055472 import sympy
%o A055472 [n*(n+1)/2+2 for n in range(10**6) if sympy.ntheory.primetest.isprime(n*(n+1)/2+2)] # _Chai Wah Wu_, Jul 14 2014
%Y A055472 Cf. A000040, A000217, A022856, A152948.
%K A055472 nonn
%O A055472 1,1
%A A055472 _Henry Bottomley_, Jun 27 2000