%I #6 May 02 2017 21:45:34
%S 20857,21577,21961,23761,27961,28657,29017,29761,30937,33961,34897,
%T 37897,41761,42937,49297,51361,60337,62761,65257,80761,83737,93097,
%U 107761,111337,113761,122497,132961,142537,151057,164377,173617,181537,188017,192961,218761
%N Primes of form n^2 + 20736.
%C Conjecture: sequence is infinite.
%H Reinhard Zumkeller, <a href="/A256840/b256840.txt">Table of n, a(n) for n = 1..10000</a>
%H J. Gebel, <a href="/A001014/a001014.txt">Integer points on Mordell curves</a> [Cached copy, after the original web site tnt.math.se.tmu.ac.jp was shut down in 2017]
%o (Haskell)
%o a256840 n = a256840_list !! (n-1)
%o a256840_list = [x | x <- map (+ 20736) a000290_list, a010051' x == 1]
%Y Cf. A010051, A000290; subsequence of A028916.
%Y Primes of form n^2+b^4, b fixed: A002496 (b=1), A243451 (b=2), A256775 (b=3), A256776 (b=4), A256777 (b=5), A256834 (b=6), A256835 (b=7), A256836 (b=8), A256837 (b=9), A256838 (b=10), A256839 (b=11), A256841 (b=13).
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Apr 11 2015