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 A350639 #8 Jan 10 2022 11:12:29 %S A350639 0,1,1,4,1,4,4,12,1,4,4,12,4,20,12,36,9,8,4,12,4,20,12,36,12,20,20,36, %T A350639 28,52,36,92,25,16,4,12,4,20,12,36,12,20,20,36,28,52,36,92,28,36,28, %U A350639 52,36,68,44,108,52,76,76,100,84,140,92,228,89,56,4,12,4 %N A350639 a(n) is the number of connected components in the set of cells added at stage n of the cellular automaton described in A350632. %C A350639 We only consider cells turned ON at stage n (and that were OFF in prior stages). %H A350639 Rémy Sigrist, <a href="/A350639/a350639.txt">C++ program for A350639</a> %H A350639 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %e A350639 The first 5 generations can be depicted as follows: %e A350639 +-------+ +-------+ %e A350639 | 5 | | 5 | %e A350639 | +---+-------------------+---+ | %e A350639 | | 4 | | %e A350639 +---+ +-------+---+-------+ +---+ %e A350639 | | 3 | | 3 | | %e A350639 | | +---+---+---+ | | %e A350639 | | | 2 | | | %e A350639 | +---+ +---+ +---+ | %e A350639 | | | | 1 | | | | %e A350639 | +---+ +---+ +---+ | %e A350639 | | 3 | | | | %e A350639 | | +---+---+---+ | | %e A350639 | | | | 3 | | %e A350639 +---+ +-------+---+-------+ +---+ %e A350639 | 5 | | | %e A350639 | +---+-------------------+---+ | %e A350639 | | | 5 | %e A350639 +-------+ +-------+ %e A350639 - so a(0) = 0, %e A350639 a(1) = 1, %e A350639 a(2) = 1, %e A350639 a(3) = 4, %e A350639 a(4) = 1, %e A350639 a(5) = 4. %o A350639 (C++) See Links section. %Y A350639 Cf. A350632. %K A350639 nonn %O A350639 0,4 %A A350639 _Rémy Sigrist_, Jan 09 2022