A355957 Different Fiedler pencils with repetitions of degree n.

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

Table of n, a(n) for n=1..20.

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

Adjacent sequences: A355954 A355955 A355956 * A355958 A355959 A355960

Keyword

nonn

Author

R. J. Mathar, Aug 23 2022

Status

approved