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A026397 Sum{T(n-k,k)}, 0<=k<=[ n/2 ], where T is the array in A026386. 0
1, 2, 3, 6, 10, 17, 31, 53, 92, 163, 282, 492, 863, 1501, 2621, 4582, 7987, 13946, 24354, 42489, 74179, 129497, 226000, 394523, 688670, 1202020, 2098239, 3662553, 6392969, 11159290, 19478867, 34000750, 59349706, 103596641 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..33.

Index entries for linear recurrences with constant coefficients, signature (0,1,3,1).

FORMULA

Pairwise sums of A026385. - Ralf Stephan, Jul 22 2003

G.f.: [(1+x)(1+x+x^2)]/[1-x^2-3x^3-x^4]. - Ralf Stephan, Apr 30 2004

MATHEMATICA

LinearRecurrence[{0, 1, 3, 1}, {1, 2, 3, 6}, 40] (* Harvey P. Dale, Apr 15 2015 *)

CROSSREFS

Sequence in context: A135431 A123908 A233268 * A193200 A026779 A081028

Adjacent sequences:  A026394 A026395 A026396 * A026398 A026399 A026400

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified December 9 08:41 EST 2021. Contains 349627 sequences. (Running on oeis4.)