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 A122981 #7 May 08 2018 15:11:56
%S A122981 3,7,12,15,37,73,31,103,146,319,731,63,271,505,1191,1833,4618
%N A122981 Number of distributive sublattices of the lattice of k-tuples less than the n-th partition (in Abramowitz and Stegun order).
%C A122981 After a(18) - for partition [1^5] - the sequence continues ?, 127, 687, 1611, 2102, 4031, 8589, ?, ?, ?, ?, ?, 255.
%H A122981 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
%e A122981 For a(5), partition [2,1], the lattice consists of the 6 pairs (i,j) where 0<=i<=2 and 0<=j<=1, with (i,j) <= (i',j') iff i<=i' and j<=j'. {(2,1), (2,0), (0,1), (0,0)} is one distributive sublattice.
%Y A122981 Cf. A122978, A122982, A122979, A036036, A074139.
%K A122981 more,nonn
%O A122981 1,1
%A A122981 _Franklin T. Adams-Watters_, Sep 21 2006