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 A300787 #12 Dec 11 2019 09:50:23
%S A300787 1,1,1,2,3,4,6,8,12,15,21,27,38,47,63,79,106,130,170,209,272,330,422,
%T A300787 512,653,784,986,1183,1482,1765,2191,2604,3218,3804,4666,5504,6726,
%U A300787 7898,9592,11240,13602,15880,19122,22277,26733,31048,37102,43003,51232,59220
%N A300787 Number of integer partitions of n in which the even parts appear as often at even positions as at odd positions.
%e A300787 The a(7) = 8 partitions: (7), (511), (421), (331), (322), (31111), (22111), (1111111). Missing are: (61), (52), (43), (4111), (3211), (2221), (211111).
%t A300787 cobal[y_]:=Sum[(-1)^x,{x,Join@@Position[y,_?EvenQ]}];
%t A300787 Table[Length[Select[IntegerPartitions[n],cobal[#]===0&]],{n,0,50}]
%Y A300787 Even- and odd-indexed terms are A006330 and A001523 respectively, which add up to A000712.
%Y A300787 Cf. A000898, A001405, A026010, A045931, A058696, A063886, A097613, A130780, A171966, A239241, A300788, A300789.
%K A300787 nonn
%O A300787 0,4
%A A300787 _Gus Wiseman_, Mar 12 2018