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 A359126 #22 Jul 09 2025 04:59:44 %S A359126 0,8,52,372,2894,23966,208086,1874508,17390158,165248499,1601857338, %T A359126 15790898316,157915304928,1598927475749,16365689821454, %U A359126 169113248927772,1762344520554606,18504654979649615,195620858324078190,2080695883684277190,22254407183551916850 %N A359126 A000168(n+1) - A000139(n). %C A359126 Number of separable rooted planar maps with n+1 edges. - _Noam Zeilberger_, Dec 26 2022 %H A359126 W. T. Tutte, <a href="http://dx.doi.org/10.4153/CJM-1963-029-x">A Census of Planar Maps</a>, Canad. J. Math. 15 (1963), 249-271. %F A359126 a(n) ~ ((48^(n + 1) - 3^(3*n + 1/2)))/(2^(2*n + 1)*sqrt(Pi)*n^(5/2)). - _Peter Luschny_, Dec 26 2022 %F A359126 D-finite with recurrence -2*(389*n-1012)*(2*n+1)*(n+3)*(n+1)*a(n) +3*(14101*n^4-20062*n^3-56389*n^2+45022*n-6072)*a(n-1) +18*(-20677*n^4+100317*n^3-137223*n^2+14267*n+52524)*a(n-2) +108*(547*n-956)*(3*n-7)*(2*n-3)*(3*n-8)*a(n-3)=0. - _R. J. Mathar_, Jan 25 2023 %p A359126 a := n -> 2*(3^(n + 1)*(2*n + 2)!/(n + 3)! - (3*n)!/(2*n + 1)!)/(n + 1)!: %p A359126 seq(a(n), n = 0..20); # _Peter Luschny_, Dec 26 2022 %Y A359126 Cf. A000139, A000168. %K A359126 nonn %O A359126 0,2 %A A359126 _N. J. A. Sloane_, Dec 23 2022, following a suggestion from _Doron Zeilberger_