login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 16:48 EDT 2022. Contains 354110 sequences. (Running on oeis4.)