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A023557
Convolution of A023531 and Fibonacci numbers.
0
0, 1, 1, 2, 4, 6, 10, 16, 27, 43, 70, 113, 183, 297, 480, 777, 1257, 2034, 3291, 5326, 8617, 13943, 22560, 36503, 59063, 95566, 154630, 250196, 404826, 655022, 1059848, 1714870, 2774718, 4489588, 7264307, 11753895, 19018202, 30772097, 49790299, 80562396, 130352695, 210915091, 341267786
OFFSET
1,4
FORMULA
a(n) = a(n-1)+a(n-2)+1 if n mod 4 = 0, else a(n) = a(n-1)+a(n-2), with offset 0. [Gary Detlefs, Dec 05 2010]
PROG
(PARI) a(n) = sum(k=1, n, issquare(8*k+9)*fibonacci(n-k+1)); \\ Michel Marcus, Jan 26 2023
CROSSREFS
Sequence in context: A293077 A000801 A080105 * A293671 A173434 A255126
KEYWORD
nonn
EXTENSIONS
More terms from Michel Marcus, Jan 26 2023
STATUS
approved