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 A217621 #21 Sep 08 2022 08:46:04 %S A217621 43,331,2311,3931,7351,8971,18043,19231,23011,31543,33091,37951,46771, %T A217621 50551,58543,60631,81043,133711,149731,173671,188143,226843,251791, %U A217621 296251,310291,319831,364543,385351,395971,412171,417643,439891,474343,540871,625111,631843 %N A217621 Primes of the form 2*n^2 + 90*n + 43. %C A217621 Conjecture: 2^a(n)-1 is not prime; in other words, these primes are included in A054723. %C A217621 2*a(n) + 1939 is a square. - _Vincenzo Librandi_, Apr 09 2015 %H A217621 Vincenzo Librandi, <a href="/A217621/b217621.txt">Table of n, a(n) for n = 1..3000</a> %t A217621 Select[Table[2 n^2 + 90 n + 43, {n, 0, 700}], PrimeQ] %o A217621 (Magma) [a: n in [0..700] | IsPrime(a) where a is 2*n^2+90*n+43]; %Y A217621 Cf. Primes of the form 2*n^2+2*(2*k+3)*n+(2*k+1): A176549 (k=0), A154577 (k=2), A154592 (k=3), A154601 (k=4), A217494 (k=7), A217495 (k=10), A217496 (k=11), A217497 (k=12), A217498 (k=13), A217499 (k=16), A217500 (k=17), A217501 (k=18), A217620 (k=19), this sequence (k=21). %Y A217621 Subsequence of A002145. %K A217621 nonn,easy %O A217621 1,1 %A A217621 _Vincenzo Librandi_, Oct 09 2012