A283839 Row sums of A283838.

1, 3, 6, 12, 24, 42, 76, 136, 240, 424, 753, 1337, 2388, 4280, 7706, 13940, 25332, 46224, 84696, 155786, 287574, 532624, 989554, 1843744, 3444389, 6450369, 12107004, 22771642, 42913116, 81014528, 153199818, 290152952, 550332614, 1045234672, 1987731140

Offset

8,2

Comments

a(n) is odd for n >= 8 and n in { A247375 }. - Alois P. Heinz, Mar 26 2017

Links

Alois P. Heinz, Table of n, a(n) for n = 8..1000

Stefano Bilotta, Variable-length Non-overlapping Codes, arXiv preprint arXiv:1605.03785, 2016

Maple

b:= proc(n, l, c, k) option remember; `if`(n=0, l,
      b(n-1, 1-l, 1, k)+`if`(c=k-1, 0, b(n-1, l, c+1, k)))
    end:
a:= proc(n) option remember; `if`(n<8, 0, a(n-1)+
      add(b(n-2*k-1, 0, 1, k), k=3..floor(n/2)-1))
    end:
seq(a(n), n=8..60);  # Alois P. Heinz, Mar 26 2017

Mathematica

nMax = 60; gf[k_] := gf[k] = x^(2k)(x-x^k)^2 / ((1-x)(1-x^k)(1-2x+x^k)) + O[x]^(nMax+1); a[n_] := Sum[SeriesCoefficient[gf[k], n], {k, 3, Floor[ n/2] - 1}]; Table[a[n], {n, 8, nMax}] (* Jean-François Alcover, Apr 05 2017 *)

Crossrefs

Cf. A247375, A283838.

Sequence in context: A330132 A039695 A079079 * A336758 A364497 A132974

Adjacent sequences: A283836 A283837 A283838 * A283840 A283841 A283842

Keyword

nonn

Author

N. J. A. Sloane, Mar 25 2017

Extensions

More terms from Alois P. Heinz, Mar 26 2017

Status

approved