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 A292700 #41 Sep 27 2017 09:17:16 %S A292700 0,0,0,2,4,40,756,8466,70664,788240,11086299,114208465,1536869680, %T A292700 19129734630,228346732944,3059857239120,38601632542723, %U A292700 509554928113867,6793745301391293,92409631618813044,1240139159309482820,16995549322569645324,236256012348427662180 %N A292700 1/4 of the number of paths that are made of alternate vertical and horizontal 4*n consecutive prime (> 2 and < prime(4*n+2)) steps. (Each path begins and ends at the same point but is allowed to intersect itself.) %F A292700 Constant term in the expansion of (1/4) * Product_{k=1..2*n} (x^prime(2*k) + 1/x^prime(2*k)) * Product_{k=1..2*n} (y^prime(2*k+1) + 1/y^prime(2*k+1)). %F A292700 a(n) = A292698(n) * A292699(n). %e A292700 U, D, L and R express up, down, left and right. %e A292700 n = 4: %e A292700 3R, 5U, 7L, 11D, 13L, 17U, 19R, 23U, 29L, 31U, 37R, 41U, 43R, 47D, 53L, 59D. %e A292700 3R, 5U, 7L, 11U, 13L, 17D, 19R, 23U, 29L, 31U, 37R, 41D, 43R, 47U, 53L, 59D. %Y A292700 Cf. A000040, A007219, A292698, A292699. %K A292700 nonn %O A292700 1,4 %A A292700 _Seiichi Manyama_, Sep 21 2017