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Number of ways to write n as an ordered sum of seven positive Fibonacci numbers (with a single type of 1).
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%I #24 Oct 10 2022 16:11:04

%S 1,7,28,77,168,308,504,750,1050,1400,1813,2261,2737,3227,3753,4312,

%T 4921,5579,6230,6832,7413,8008,8652,9289,9996,10654,11361,12061,12853,

%U 13657,14357,14924,15393,15869,16408,16933,17689,18319,18949,19537,20244,21049,21728

%N Number of ways to write n as an ordered sum of seven positive Fibonacci numbers (with a single type of 1).

%F G.f.: ( Sum_{k>=2} x^Fibonacci(k) )^7.

%F a(n) = A121548(n,7).

%t nmax = 49; CoefficientList[Series[Sum[x^Fibonacci[k], {k, 2, 21}]^7, {x, 0, nmax}], x] // Drop[#, 7] &

%Y Cf. A000045, A076739, A121548, A121549, A121550, A319400, A357688, A357690, A357691, A357716, A357717.

%K nonn

%O 7,2

%A _Ilya Gutkovskiy_, Oct 10 2022