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 A347842 a(n) is the number of (strict) chains of subspaces with ends 0 and (F_4)^n. 2
 1, 6, 148, 14808, 5942608, 9546508128, 61355108818240, 1577381936031968640, 162213856617581098030336, 66726795842176170072717129216, 109792555585903911536355551233758208, 722612693482570097701467493432061846673408 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Álvar Ibeas, Table of n, a(n) for n = 1..40 FORMULA a(n) = Sum_{L partition of n} A347487(n, L) * A036038(len(L), sig(L)), where sig(L) is the partition composed by the part multiplicities of L. EXAMPLE a(3) = 148 = 1 * 1 + 21 * 2 + 105 * 1, counting: the unrefined chain 0 < (F_4)^3; 21 chains 0 < V < (F_4)^3, with dim(V) = 1; another 21 chains 0 < V < (F_4)^3, with dim(V) = 2; and 105 chains 0 < V_1 < V_2 < (F_4)^3. CROSSREFS Cf. A289545, A347487, A036038. Sequence in context: A065986 A199226 A012791 * A264645 A089480 A056427 Adjacent sequences: A347839 A347840 A347841 * A347843 A347844 A347845 KEYWORD nonn AUTHOR Álvar Ibeas, Sep 15 2021 STATUS approved

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Last modified December 9 23:06 EST 2023. Contains 367696 sequences. (Running on oeis4.)