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 A256977 #11 Jan 31 2024 11:09:47
%S A256977 1,6,12,19,31,49,74,110,159,226,317,437,590,789,1043,1364,1769,2275,
%T A256977 2899,3670,4612,5758,7145,8814,10812,13202,16040,19396,23354,28006,
%U A256977 33447,39801,47188,55753,65659,77083,90216,105288,122530,142211
%N A256977 G.f.: (1 + 5*x + 5*x^2 + x^3)/Product_{i=1..10} (1 - x^i).
%D A256977 J. C. P. Miller, On the enumeration of partially ordered sets of integers, pp. 109-124 of T. P. McDonough and V. C. Mavron, editors, Combinatorics: Proceedings of the Fourth British Combinatorial Conference 1973. London Mathematical Society, Lecture Note Series, Number 13, Cambridge University Press, NY, 1974. The g.f. is G(t) at the foot of page 123.
%H A256977 Ray Chandler, <a href="/A256977/b256977.txt">Table of n, a(n) for n = 0..1000</a>
%H A256977 <a href="/index/Rec#order_54">Index entries for linear recurrences with constant coefficients</a>, signature (2, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 3, -2, 3, -1, 1, -1, 0, -1, 0, -1, -2, 2, -2, 3, -2, 4, -2, 3, -2, 2, -2, -1, 0, -1, 0, -1, 1, -1, 3, -2, 3, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 2, -1).
%p A256977 (1+5*x+5*x^2+x^3)/mul(1-x^i,i=1..10);
%K A256977 nonn
%O A256977 0,2
%A A256977 _N. J. A. Sloane_, Apr 23 2015