# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a292051 Showing 1-1 of 1 %I A292051 #8 Sep 08 2017 09:12:06 %S A292051 0,1,14,42,124,251,506,852,1432,2165,3270,4606,6484,8687,11634,15016, %T A292051 19376,24297,30462,37330,45740,55011,66154,78332,92744,108381,126646, %U A292051 146342,169092,193495,221410,251216,285024,320977,361454,404346,452316,502987,559322,618660 %N A292051 Wiener index of the n X n black bishop graph. %H A292051 Eric Weisstein's World of Mathematics, Black Bishop Graph %H A292051 Eric Weisstein's World of Mathematics, Wiener Index %H A292051 Index entries for linear recurrences with constant coefficients, signature (2,2,-6,0,6,-2,-2,1). %F A292051 a(n) = (3 - 10*n + 6*n^2 - 8*n^3 + 6*n^4 - 3*(-1)^n*(1 - 2*n + 2*n^2))/24. %F A292051 a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8). %F A292051 G.f.: x^2*(-1 - 12*x - 12*x^2 - 18*x^3 - 3*x^4 - 2*x^5)/((-1 + x)^5*(1 + x)^3). %t A292051 Table[(3 - 10 n + 6 n^2 - 8 n^3 + 6 n^4 - 3 (-1)^n (1 - 2 n + 2 n^2))/24, {n, 20}] %t A292051 LinearRecurrence[{2, 2, -6, 0, 6, -2, -2, 1}, {0, 1, 14, 42, 124, 251, 506, 852}, 20] %t A292051 CoefficientList[Series[x (-1 - 12 x - 12 x^2 - 18 x^3 - 3 x^4 - 2 x^5)/((-1 + x)^5 (1 + x)^3), {x, 0, 20}], x] %K A292051 nonn,easy %O A292051 1,3 %A A292051 _Eric W. Weisstein_, Sep 08 2017 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE