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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
OFFSET
1,2
LINKS
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
KEYWORD
nonn
AUTHOR
Álvar Ibeas, Sep 15 2021
STATUS
approved