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 A001832 M3063 N1241 #63 Feb 16 2025 08:32:24 %S A001832 1,1,3,19,195,3031,67263,2086099,89224635,5254054111,426609529863, %T A001832 47982981969979,7507894696005795,1641072554263066471, %U A001832 502596525992239961103,216218525837808950623459,130887167385831881114006475,111653218763166828863141636911 %N A001832 Number of labeled connected bipartite graphs on n nodes. %D A001832 Miklos Bona, editor, Handbook of Enumerative Combinatorics, CRC Press, 2015, p. 406. %D A001832 R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1976. %D A001832 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001832 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A001832 T. D. Noe, <a href="/A001832/b001832.txt">Table of n, a(n) for n = 1..50</a> %H A001832 F. Harary and R. W. Robinson, <a href="http://dx.doi.org/10.4153/CJM-1979-007-3">Labeled bipartite blocks</a>, Canad. J. Math., 31 (1979), 60-68. %H A001832 F. Harary and R. W. Robinson, <a href="/A001832/a001832.pdf">Labeled bipartite blocks</a>, Canad. J. Math., 31 (1979), 60-68. (Annotated scanned copy) %H A001832 D. A. Klarner, <a href="http://dx.doi.org/10.1016/S0021-9800(69)80100-6">The number of graded partially ordered sets</a>, J. Combin. Theory, 6 (1969), 12-19. %H A001832 D. A. Klarner, <a href="/A000798/a000798_11.pdf">The number of graded partially ordered sets</a>, J. Combin. Theory, 6 (1969), 12-19. [Annotated scanned copy] %H A001832 A. Nymeyer and R. W. Robinson, <a href="/A000684/a000684.pdf">Tabulation of the Numbers of Labeled Bipartite Blocks and Related Classes of Bicolored Graphs</a>, 1982 [Annotated scanned copy of unpublished MS and letter from R.W.R.] %H A001832 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/n-ColorableGraph.html">n-Colorable Graph</a> %H A001832 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/n-ChromaticGraph.html">n-Chromatic Graph</a> %F A001832 E.g.f.: log(A(x))/2 where A(x) is e.g.f. of A047863. %F A001832 a(n) = A002031(n)/2, for n > 1. - _Geoffrey Critzer_, May 10 2011 %t A001832 mx = 17; s = Sum[ Binomial[n, k] 2^(k (n - k)) x^n/n!, {n, 0, mx}, {k, 0, n}] ; Range[0, mx]! CoefficientList[ Series[ Log[s]/2, {x, 0, mx}], x] (* _Geoffrey Critzer_, May 10 2011 *) %o A001832 (PARI) seq(n)=Vec(serlaplace(log(sum(k=0, n, exp(2^k*x + O(x*x^n))*x^k/k!))/2)) \\ _Andrew Howroyd_, Sep 26 2018 %Y A001832 Row sums of A228861. %Y A001832 The unlabeled version is A005142. %Y A001832 Cf. A002031, A047863, A047864. %K A001832 nonn,nice,easy %O A001832 1,3 %A A001832 _N. J. A. Sloane_ %E A001832 More terms from _Vladeta Jovovic_, Apr 12 2003