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A023860 a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2), t = A000045 (Fibonacci numbers). 1
1, 1, 4, 7, 17, 27, 56, 91, 172, 278, 498, 806, 1395, 2257, 3820, 6181, 10307, 16677, 27534, 44551, 73064, 118220, 193012, 312300, 508341, 822513, 1336132, 2161907, 3507189, 5674751, 9197732, 14882243, 24107124, 39006146, 63159782 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

MATHEMATICA

Table[Sum[j*Fibonacci[n+1-j], {j, 1, Floor[(n+1)/2]}], {n, 1, 50}] (* G. C. Greubel, Jun 12 2019 *)

PROG

(PARI) a(n) = sum(j=1, floor((n+1)/2), j*fibonacci(n+1-j)); \\ G. C. Greubel, Jun 12 2019

(MAGMA) [(&+[j*Fibonacci(n+1-j): j in [1..Floor((n+1)/2)]]): n in [1..50]]; // G. C. Greubel, Jun 12 2019

(Sage) [sum(j*fibonacci(n+1-j) for j in (1..floor((n+1)/2))) for n in (1..50)] # G. C. Greubel, Jun 12 2019

CROSSREFS

Sequence in context: A034736 A236564 A302549 * A009881 A049944 A098091

Adjacent sequences:  A023857 A023858 A023859 * A023861 A023862 A023863

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Title simplified, a(15) corrected and more terms from Sean A. Irvine, Jun 11 2019

STATUS

approved

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Last modified November 19 06:26 EST 2019. Contains 329310 sequences. (Running on oeis4.)