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 A270883 #29 May 21 2017 09:31:18
%S A270883 1,1,3,29,961,110657,45148929,66294748161,355213310611457,
%T A270883 7025248750804353025,517789725632146766102529,
%U A270883 143350189472963401121415823361,150053549525040193876302690826321921,597137918840965720442548744290289324130305,9075744511279922489436849557317778793074029232129
%N A270883 Row sums of triangle A270882. Number of direct-sum decompositions of an n-dimensional vector space over GF(2) with any given nonzero vector in a block.
%H A270883 David Ellerman, <a href="http://arxiv.org/abs/1603.07619">The number of direct-sum decompositions of a finite vector space</a>, arXiv:1603.07619 [math.CO], 2016.
%H A270883 David Ellerman, <a href="http://arxiv.org/abs/1604.01087">The Quantum Logic of Direct-Sum Decompositions</a>, arXiv preprint arXiv:1604.01087 [quant-ph], 2016. See Section 7.5.
%F A270883 Recurrence: a(n) = Sum_{k=0,...,n-1} q-binomial(n-1,k)*q^(n*(n-k))*D_q(k) where D_q(k) is given by A270881 for q = 2 and where the q-binomial for q = 2 is given by A022166. This summation formula is the q-analog of the summation formula for the Bell numbers A000110 when q = 1. - _David P. Ellerman_, Mar 26 2016
%Y A270883 Cf. A270881, A270882.
%K A270883 nonn
%O A270883 0,3
%A A270883 _Michel Marcus_, Mar 25 2016
%E A270883 Name edited by _David P. Ellerman_, Mar 26 2016
%E A270883 a(8)-a(14) from _Geoffrey Critzer_, May 21 2017