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 A183064 #19 Sep 14 2015 16:07:42 %S A183064 7,41,8119,47321,63018038201,2470433131948081,96845919575610633161, %T A183064 19175002942688032928599,5834531641231893991002972081099601, %U A183064 6733044458057842709277507685523012161,228725309250740208744750893347264645481 %N A183064 Numbers k such that k^2+1 = 2*p^2, p prime. %C A183064 Subset of A002315 (Numbers k such that k^2 + 1 = 2*q^2). %H A183064 Charles R Greathouse IV, <a href="/A183064/b183064.txt">Table of n, a(n) for n = 1..22</a> %e A183064 a(2) = 41 because 41^2+1 = 2*29^2. %p A183064 with(numtheory):for n from 1 to 1000000 do : p:=ithprime(n):x:=2*p^2: y:=sqrt(x-1):if %p A183064 y=floor(y) then print(y):else fi:od: %o A183064 (PARI) list(lim)=my(v=List(),w=3+quadgen(32),k,n); while((k=imag((1+w)*w^n++))<=lim, if(ispseudoprime(sqrtint((k^2+1)/2)), listput(v,k))); Vec(v) \\ _Charles R Greathouse IV_, Sep 14 2015 %Y A183064 Cf. A002315, A005574, A002731, A174492. %K A183064 nonn %O A183064 1,1 %A A183064 _Michel Lagneau_, Feb 01 2011 %E A183064 More terms from _Charles R Greathouse IV_, Feb 01 2011