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 A025574 #12 Sep 08 2019 00:53:47 %S A025574 1,10,61,356,2058,11892,68860,399828,2328066,13591364,79538750, %T A025574 466489520,2741310614,16137748980,95152639095,561856988100, %U A025574 3322001296650,19664909435556,116535288360106,691284470658376,4104450497833036,24390520567203960,145053186645586383 %N A025574 T(2n,n+1), where T is the array defined in A025564. %C A025574 Coefficient of y^(n+1) in (y^2+2*y+1)*(y^2+y+1)^(2*n-2). - _Robert Israel_, Sep 07 2019 %H A025574 Robert Israel, <a href="/A025574/b025574.txt">Table of n, a(n) for n = 1..1278</a> %p A025574 f:= n -> coeff((y^2+2*y+1)*(y^2+y+1)^(2*n-2),y,n+1); %p A025574 map(f, [$1..30]); # _Robert Israel_, Sep 07 2019 %Y A025574 Cf. A025564. %K A025574 nonn %O A025574 1,2 %A A025574 _Clark Kimberling_ %E A025574 More terms from _Sean A. Irvine_, Sep 07 2019