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 A221472 #3 Feb 13 2013 02:04:27
%S A221472 0,1,2,5,6,14,57
%N A221472 Integers n such that n^2 is the difference of two Lucas numbers (A000204).
%C A221472 This sequence is similar to the one for Fibonacci numbers (A219114) and appears to be finite also. See A221471 for an infinite version of this sequence.
%e A221472 The only known square differences of Lucas numbers:
%e A221472 1^2 = L(3)-L(2) = 4-3,
%e A221472 2^2 = L(4)-L(2) 7-3 = L(5)-L(4) = 11-7,
%e A221472 5^2 = L(7)-l(3) = 29-4,
%e A221472 6^2 = L(8)-L(5) = 47-11,
%e A221472 14^2 = L(11)-L(2) = 199-3,
%e A221472 57^2 = L(17)-L(12) = 3571-322.
%t A221472 t = Union[Flatten[Abs[Table[LucasL[n] - LucasL[i], {n, 120}, {i, n}]]]]; t2 = Select[t, IntegerQ[Sqrt[#]] &]; Sqrt[t2]
%Y A221472 Cf. A000032 (Lucas numbers), A113191 (difference of two Lucas numbers).
%Y A221472 Cf. A219114 (corresponding sequence for Fibonacci numbers).
%K A221472 nonn
%O A221472 1,3
%A A221472 _T. D. Noe_, Feb 13 2013