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 A309073 #9 Jul 11 2019 16:31:17 %S A309073 26,6,6,76,14,12,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,712,38,280, %T A309073 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, %U A309073 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6 %N A309073 Split the sequence A247476 into nonempty chunks of minimal length such that for d = 1..9, the number of terms with leading digit d is even; a(n) is the length of the n-th chunk. %C A309073 This sequence corresponds to the first difference of A309063. %H A309073 Rémy Sigrist, <a href="/A309073/b309073.txt">Table of n, a(n) for n = 1..10000</a> %H A309073 Rémy Sigrist, <a href="/A309073/a309073.png">Illustration of first terms</a> %F A309073 a(n) = A309063(n+1) - A309063(n). %F A309073 a(n) = A055642(A309072(n)). %e A309073 See illustration of first terms in Links section. %Y A309073 Cf. A247476, A309063, A309072. %K A309073 nonn,base %O A309073 1,1 %A A309073 _Rémy Sigrist_, Jul 10 2019