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 A065340 #15 Oct 25 2017 06:01:33 %S A065340 2,28,182,864,3474,12660,43358,142552,455930,1430796,4431078,13595664, %T A065340 41441570,125732836,380212142,1147057800,3454803594,10393245180, %U A065340 31240551350,93849578560,281817169202,846013542228,2539215029502,7620094559544,22865383949594 %N A065340 Third diagonal of triangle in A046740. %H A065340 D. P. Roselle, <a href="http://dx.doi.org/10.1090/S0002-9939-1968-0218256-9">Permutations by number of rises and successions</a>, Proc. Amer. Math. Soc., 19 (1968), 8-16. %H A065340 D. P. Roselle, <a href="/A046739/a046739.pdf"> Permutations by number of rises and successions</a>, Proc. Amer. Math. Soc., 19 (1968), 8-16. [Annotated scanned copy] %H A065340 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (10,-40,82,-91,52,-12). %F A065340 a(n) = 3^n-(3*n+1)*2^(n-1)+2*n^2-2*n+1. - _Vladeta Jovovic_, Jan 04 2003 %F A065340 G.f.: -2*x^4*(9*x^2-4*x-1) / ((x-1)^3*(2*x-1)^2*(3*x-1)). [_Colin Barker_, Feb 03 2013] %o A065340 (PARI) a(n) = 3^n-(3*n+1)*2^(n-1)+2*n^2-2*n+1; \\ _Michel Marcus_, Oct 25 2017 %Y A065340 Cf. A046740. %K A065340 nonn,easy %O A065340 4,1 %A A065340 _N. J. A. Sloane_, May 15 2002 %E A065340 More terms from _Colin Barker_, Feb 03 2013