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 A061524 #9 Aug 13 2020 14:01:06 %S A061524 224,705,1600,3065,5280,8449,12800,18585,26080,35585,47424,61945, %T A061524 79520,100545,125440,154649,188640,227905,272960,324345,382624,448385, %U A061524 522240,604825,696800,798849,911680,1036025,1172640,1322305,1485824,1664025 %N A061524 Surround numbers of an n X 2 rectangle when n is even. %C A061524 See A061525 for odd n. %H A061524 E. J. Friedman, <a href="https://erich-friedman.github.io/mathmagic/0599.html">Math. Magic: May, 1999</a> %F A061524 a(n) = (n^4 + 32n^3 + 344n^2 + 768n + 400)/16 for even n. %F A061524 From _Chai Wah Wu_, Dec 20 2019: (Start) %F A061524 a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n > 6. %F A061524 G.f.: x^2*(-25*x^4 + 125*x^3 - 315*x^2 + 415*x - 224)/(x - 1)^5. (End) %Y A061524 Cf. A047875 A061525. %K A061524 easy,nonn %O A061524 2,1 %A A061524 _Jason Earls_, May 03 2001 %E A061524 More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001