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 A279904 #35 Sep 08 2022 08:46:18
%S A279904 71,6271,20971519999,3696558092582911,71248353479884799,
%T A279904 36607563614276605181951,66626319770601443076406771711,
%U A279904 46716685589841799771959773105092594214371327,3855174423960385883723562689229267550261846474751
%N A279904 Primes of the form n^2*2^n - 1.
%F A279904 a(n) = A000040(A058781(n)).
%e A279904 a(1) = 3^2*2^3 - 1 = 71 is prime where 3 = A058781(1).
%e A279904 a(2) = 7^2*2^7 - 1 = 6271 is prime where 7 = A058781(2).
%t A279904 Select[Table[n^2 2^n - 1, {n, 0, 150}], PrimeQ] (* _Vincenzo Librandi_, Jan 20 2017 *)
%o A279904 (Magma) [a: n in [1..45] | IsPrime(a) where a is n^2*2^n-1];
%o A279904 (PARI) select(ispseudoprime, apply(n->n^2*2^n - 1, [1..200])) \\ _Charles R Greathouse IV_, Jan 20 2017
%Y A279904 Cf. A058781.
%K A279904 nonn
%O A279904 1,1
%A A279904 _Juri-Stepan Gerasimov_, Jan 17 2017