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 A256777 #8 Aug 27 2025 16:05:42 %S A256777 641,661,769,821,881,1109,1201,1301,1409,2069,2389,2741,3329,3541, %T A256777 3761,3989,4721,6101,6709,7349,7681,8369,9461,12289,14081,14549,16001, %U A256777 18049,19121,20789,25589,28181,31601,32309,33749,35221,35969,37489,38261,39041,39829 %N A256777 Primes of form n^2 + 625. %C A256777 Conjecture: sequence is infinite. %H A256777 Reinhard Zumkeller, <a href="/A256777/b256777.txt">Table of n, a(n) for n = 1..10000</a> %t A256777 Select[Range[200]^2+625,PrimeQ] (* _Harvey P. Dale_, Aug 27 2025 *) %o A256777 (Haskell) %o A256777 a256777 n = a256777_list !! (n-1) %o A256777 a256777_list = [x | x <- map (+ 625) a000290_list, a010051' x == 1] %o A256777 (PARI) list(lim)=if(lim<641,return([])); my(v=List(),t); forstep(n=4, sqrtint(lim\1-625), 2, if(isprime(t=n^2+625), listput(v,t))); Vec(v) \\ _Charles R Greathouse IV_, Aug 18 2017 %Y A256777 Cf. A010051, A000290; subsequence of A028916. %Y A256777 Primes of form n^2+b^4, b fixed: A002496 (b=1), A243451 (b=2), A256775 (b=3), A256776 (b=4), A256834 (b=6), A256835 (b=7), A256836 (b=8), A256837 (b=9), A256838 (b=10), A256839 (b=11), A256840 (b=12), A256841 (b=13). %K A256777 nonn,changed %O A256777 1,1 %A A256777 _Reinhard Zumkeller_, Apr 11 2015