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 A228582 #21 May 19 2017 15:44:55
%S A228582 0,0,0,0,2,32,198,868,2860,7984,19380,42696,86526,164560,296010,
%T A228582 509132,841464,1345184,2086920,3155472,4660890,6745152,9580142,
%U A228582 13381940,18407268,24972112,33446140,44276440,57979350,75170160,96551730
%N A228582 The number of binary pattern classes in the (2,n)-rectangular grid with 7 '1's and (2n-7) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other.
%C A228582 Column 7 of A226048.
%H A228582 Vincenzo Librandi, <a href="/A228582/b228582.txt">Table of n, a(n) for n = 0..1000</a>
%F A228582 a(n) = (1/4)*(binomial(2*n, 7) + 2*binomial(n-1, 3)*(1/2)*(1-(-1)^n)) = (n-3)*(n-2)*(n-1)(2*n*(2n-5)*(2*n-3)*(2*n-1)-105*(-1)^n+105)/2520.
%F A228582 G.f.: 2*x^4*(2*x^7 +7*x^6 +48*x^5 +67*x^4 +82*x^3 +37*x^2 +12*x +1) / ((x+1)^4*(x-1)^8). [_Bruno Berselli_, Aug 27 2013]
%t A228582 CoefficientList[Series[2 x^4 (2 x^7 + 7 x^6 + 48 x^5 + 67 x^4 + 82 x^3 + 37 x^2 + 12 x + 1) / ((x + 1)^4 (x - 1)^8), {x, 0, 40}], x] (* _Vincenzo Librandi_, Aug 27 2013 *)
%o A228582 (R) a <- 0
%o A228582 for(n in 1:40) a[n+1] <- (1/4)*(choose(2*(n+2), 7) + 2*choose(n+1, 3)*(1/2)*(1-(-1)^n))
%o A228582 a
%Y A228582 Cf. A226048.
%K A228582 nonn,easy
%O A228582 0,5
%A A228582 _Yosu Yurramendi_, _María Merino_, Aug 26 2013
%E A228582 Formula adapted to the offset from _Bruno Berselli_, Aug 27 2013