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A023665 Convolution of A000201 and A023533. 2

%I #7 Jul 18 2022 09:58:24

%S 1,3,4,7,11,13,17,20,23,28,32,37,43,47,52,57,61,67,71,77,84,90,97,103,

%T 109,117,122,129,136,141,149,155,161,169,175,184,192,199,209,215,224,

%U 232,240,249,256,264,274,280,289,297,304,314,321,329,337

%N Convolution of A000201 and A023533.

%H G. C. Greubel, <a href="/A023665/b023665.txt">Table of n, a(n) for n = 1..5000</a>

%F a(n) = Sum_{j=1..n} A000201(j) * A023533(n-j+1).

%F T(n, k) = Sum_{j=1..n} A000201(k+1 +binomial(n+2,3) -binomial(j+2,3)), for 0 <= k <= n*(n+3)/2, n >= 1 (as an irregular triangle). - _G. C. Greubel_, Jul 18 2022

%t Table[Sum[Floor[(k+1 +Binomial[n+2,3] -Binomial[j+2,3])*GoldenRatio], {j,n}], {n, 7}, {k,0,n*(n+3)/2}] (* _G. C. Greubel_, Jul 18 2022 *)

%o (Magma)

%o A023533:= func< n | Binomial(Floor((6*n-1)^(1/3)) +2, 3) ne n select 0 else 1 >;

%o [(&+[Floor(k*(1+Sqrt(5))/2)*A023533(n-k+1): k in [1..n]]): n in [1..80]]; // _G. C. Greubel_, Jul 18 2022

%o (SageMath)

%o def A023665(n, k): return sum( floor((k+1 + binomial(n+2,3) - binomial(j+2,3))*golden_ratio) for j in (1..n) )

%o flatten([[A023665(n,k) for k in (0..n*(n+3)/2)] for n in (1..7)]) # _G. C. Greubel_, Jul 18 2022

%Y Cf. A000201, A001622, A023533.

%K nonn

%O 1,2

%A _Clark Kimberling_

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Last modified April 23 11:35 EDT 2024. Contains 371912 sequences. (Running on oeis4.)