A053135 Binomial coefficients C(2*n+6,6).
1, 28, 210, 924, 3003, 8008, 18564, 38760, 74613, 134596, 230230, 376740, 593775, 906192, 1344904, 1947792, 2760681, 3838380, 5245786, 7059052, 9366819, 12271512, 15890700, 20358520, 25827165, 32468436, 40475358, 50063860, 61474519, 74974368, 90858768
Offset: 0
Links
- Nathaniel Johnston, Table of n, a(n) for n = 0..1000
- Milan Janjić, Enumerative Formulas for Some Functions on Finite Sets.
- Milan Janjić, Two Enumerative Functions.
- Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
Programs
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Magma
[Binomial(2*n+6, 6): n in [0..30]]; // G. C. Greubel, Sep 03 2018
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Maple
seq(binomial(2*n+6,6),n=0..40); # Nathaniel Johnston, May 14 2011
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Mathematica
Table[Binomial[2*n+6, 6], {n, 0, 30}] (* G. C. Greubel, Sep 03 2018 *)
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PARI
vector(30,n,n--; binomial(2*n+6, 6)) \\ G. C. Greubel, Sep 03 2018
Formula
G.f.: (1 + 21*x + 35*x^2 + 7*x^3)/(1-x)^7.
a(n) = binomial(2*n+6, 6) = A000579(2*n+6).
E.g.f.: (90 + 2430*x + 6975*x^2 + 5655*x^3 + 1710*x^4 + 204*x^5 + 8*x^6)* exp(x)/90. - G. C. Greubel, Sep 03 2018
From Amiram Eldar, Oct 21 2022: (Start)
Sum_{n>=0} 1/a(n) = 96*log(2) - 131/2.
Sum_{n>=0} (-1)^n/a(n) = 23/2 - 6*Pi + 12*log(2). (End)
Comments