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A355957
Different Fiedler pencils with repetitions of degree n.
1
1, 6, 37, 254, 1958, 16910, 162839, 1738846, 20469724, 264061262, 3710515665, 56463372510, 925339183634, 16248435935342, 304279525428443, 6051490582876670, 127336699707863032, 2825520081496305262, 65918580247670293685, 1612619297571639402174
OFFSET
1,2
COMMENTS
In essence the self-convolution of A005189 (omitting the first 2 terms).
LINKS
Poloni, Federico; Del Corso, Gianna M. Counting Fiedler pencils with repetitions. Linear Algebra Appl. 532, 463-499 (2017), corollary 22.
FORMULA
a(n) = Sum_{g=1..n} A005189(1+g)*A005189(n-g+2).
MAPLE
A355957 := proc(d)
add(A005189(1+g)*A005189(d-g+2), g=1..d) ;
end proc:
seq(A355957(n), n=1..30) ;
CROSSREFS
Sequence in context: A080954 A271905 A351152 * A073013 A192238 A140712
KEYWORD
nonn
AUTHOR
R. J. Mathar, Aug 23 2022
STATUS
approved