cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A329444 The sixth moments of the squared binomial coefficients; a(n) = Sum_{m=0..n} m^6*binomial(n, m)^2.

Original entry on oeis.org

0, 1, 68, 1314, 18080, 197350, 1836792, 15233316, 115776768, 821760390, 5520171800, 35438827996, 219038609088, 1310833221724, 7629754810160, 43348888067400, 241117582878720, 1316197491501510, 7065439665315480, 37362065079691500, 194909773207512000, 1004374157379474420
Offset: 0

Views

Author

Nikita D. Gogin, Nov 16 2019

Keywords

References

  • H. W. Gould, Combinatorial Identities, 1972. (See formulas 3.77, 3.78, and 3.79 on page 31.)

Crossrefs

Programs

  • Magma
    [(&+[Binomial(n,k)^2*k^6: k in [0..n]]): n in [0..30]]; // G. C. Greubel, Jun 23 2022
    
  • Mathematica
    Table[Sum[m^6*(Binomial[n, m])^2, {m, 0, n}], {n, 21}]
  • PARI
    a(n) = sum(m=0, n, m^6*binomial(n, m)^2); \\ Jinyuan Wang, Nov 23 2019
    
  • SageMath
    [n^3*(n+1)*(n^6+3*n^5-13*n^4-15*n^3+30*n^2+8*n-2)*catalan_number(n)/(8*(2*n-1)*(2*n-3)*(2*n-5)) for n in (0..30)] # G. C. Greubel, Jun 23 2022

Formula

a(n) = binomial(2*n, n) * n^3*(n^6 + 3*n^5 - 13*n^4 - 15*n^3 + 30*n^2 + 8*n - 2)/(8*(2*n-1)*(2*n-3)*(2*n-5)).
G.f.: x*(1 + 42*x - 168*x^2 + 1648*x^3 - 7608*x^4 + 18144*x^5 - 19376*x^6 - 1440*x^7 + 14400*x^8)/((1-4*x)^6*sqrt(1-4*x)). - G. C. Greubel, Jun 23 2022

A329913 The fifth moments of the squared binomial coefficients; a(n) = Sum_{m=0..n} m^5*binomial(n, m)^2.

Original entry on oeis.org

0, 1, 36, 540, 6080, 56250, 455112, 3342192, 22809600, 146988270, 904475000, 5358254616, 30750385536, 171773279860, 937514244240, 5014575000000, 26351064760320, 136319273714070, 695429503781400, 3503580441563400, 17452918098000000, 86055711108818220
Offset: 0

Views

Author

Nikita D. Gogin, Nov 24 2019

Keywords

References

  • H. W. Gould, Combinatorial Identities, 1972. (See formulas 3.77, 3.78, and 3.79 on page 31.)

Crossrefs

Programs

  • Magma
    [(&+[Binomial(n,k)^2*k^5: k in [0..n]]): n in [0..30]]; // G. C. Greubel, Jun 23 2022
    
  • Maple
    seq( binomial(2*n,n)*n^4*(n^3 + 3*n^2 - 3*n - 5)/((16*n-8)*(2*n-3)),n=0..30); # Robert Israel, Jan 26 2020
  • Mathematica
    Table[Sum[m^5*(Binomial[n, m])^2, {m, 0, n}], {n, 21}]
  • PARI
    a(n) = sum(k=0, n, k^5*binomial(n, k)^2); \\ Michel Marcus, Nov 24 2019
    
  • SageMath
    [n^4*(n+1)*(n^3+3*n^2-3*n-5)/(8*(2*n-1)*(2*n-3))*catalan_number(n) for n in (0..30)] # G. C. Greubel, Jun 23 2022

Formula

a(n) = binomial(2*n,n)*n^4*(n^3 + 3*n^2 - 3*n - 5)/(8*(2*n-1)*(2*n-3)).
G.f.: x*(1 + 14*x - 54*x^2 + 404*x^3 - 1544*x^4 + 2880*x^5 - 2160*x^6)/(1-4*x)^(11/2). - Stefano Spezia, Jan 03 2020
(-12960 + 8640*n)*a(n) + (7200 - 13680*n)*a(n + 1) + (3920 + 9056*n)*a(n + 2) + (-4184 - 3160*n)*a(n + 3) + (1404 + 620*n)*a(n + 4) + (-584 - 110*n)*a(n + 5) + (14 + 10*n)*a(n + 6) + (n + 6)*a(n + 7) = 0. - Robert Israel, Jan 26 2020

A145436 Decimal expansion of Sum_{n>=0} (-1)^n/((2n+1)^2*binomial(2n,n)).

Original entry on oeis.org

9, 5, 0, 2, 3, 9, 6, 0, 5, 1, 1, 6, 6, 4, 3, 2, 5, 8, 9, 8, 1, 6, 2, 7, 9, 5, 2, 9, 5, 1, 4, 2, 6, 9, 0, 9, 1, 6, 9, 7, 3, 0, 8, 5, 1, 0, 5, 8, 9, 0, 1, 8, 2, 5, 2, 8, 9, 6, 5, 4, 5, 4, 3, 3, 0, 0, 6, 2, 1, 4, 3, 3, 7, 0, 2, 3, 1, 5, 4, 3, 4, 8, 7, 8, 4, 6, 5, 2, 5, 9, 3, 6, 0
Offset: 0

Views

Author

R. J. Mathar, Feb 08 2009

Keywords

Examples

			0.95023960511664325898162795295142690916973085105890...
		

References

  • Alexander Apelblat, Tables of Integrals and Series, Harri Deutsch, (1996), 4.1.45.
  • Bruce C. Berndt, Ramanujan's Notebooks, Part 1, Springer-Verlag, 1985, Chapter 9, p. 289, eq. (vii).
  • Calvin C. Clawson, Mathematical Mysteries: The Beauty and Magic of Numbers, Springer, 2013. See p. 222.

Crossrefs

Programs

  • Maple
    1/6*Pi^2-3*ln(1/2+1/2*5^(1/2))^2 ;
  • Mathematica
    RealDigits[Zeta[2] - 3 * Log[GoldenRatio]^2, 10, 120][[1]] (* Amiram Eldar, May 06 2023 *)
  • PARI
    Pi^2/6-3*log(1/2+sqrt(5)/2)^2 \\ Charles R Greathouse IV, Sep 13 2013

Formula

Equals A013661 - 3*A002390^2.

A329521 The sixth moments of the alternated squared binomial coefficients; a(n) = Sum_{m=0..n} (-1)^m*m^6*binomial(n, m)^2.

Original entry on oeis.org

0, -1, 60, -162, -5280, 20250, 128520, -569380, -1854720, 9338490, 20097000, -113704668, -181621440, 1142905764, 1447926480, -10042461000, -10529925120, 79859881530, 71384175720, -587933314540, -457825368000, 4070529226764
Offset: 0

Views

Author

Nikita D. Gogin, Nov 15 2019

Keywords

References

  • H. W. Gould, Combinatorial Identities, 1972.

Crossrefs

Programs

  • Magma
    [&+[(-1)^m*m^6*(Binomial(n,m))^2:m in [0..n]]:n in [0..21]]; // Marius A. Burtea, Nov 15 2019
    
  • Mathematica
    Table[Sum[(-1)^m*m^6*(Binomial[n, m])^2, {m, 0, n}], {n, 21}]
  • PARI
    a(n) = sum(m=0, n, (-1)^m*m^6*binomial(n , m)^2); \\ Michel Marcus, Nov 15 2019

Formula

a(n) = (-1)^((n+2)/2)*binomial(n, n/2)*(n^3*(n+1)*(3n-1)/4), if n is even,
a(n) = (-1)^((n-1)/2)*binomial(n,((n+1)/2))*(n^2*( n+1)*(n^3+n^2-9n+3)/8), if n is odd.
G.f.: x*(-1 + 60*x - 188*x^2 - 3720*x^3 + 15752*x^4 + 8400*x^5 - 90928*x^6 + 79680*x^7 + 42112*x^8 - 69120*x^9 + 17408*x^10)/(1+4*x^2)^(13/2). - Stefano Spezia, Nov 15 2019

A361719 a(n) = Sum_{k = 1..n} (-1)^(n+k) * k^3 * binomial(n,k)^2.

Original entry on oeis.org

0, 1, 4, -36, -96, 450, 1080, -3920, -8960, 28350, 63000, -182952, -399168, 1093092, 2354352, -6177600, -13178880, 33474870, 70887960, -175518200, -369512000, 896251356, 1877859984, -4478082336, -9345563136, 21971267500, 45700236400, -106148523600, -220159900800
Offset: 0

Views

Author

Peter Bala, Mar 24 2023

Keywords

Comments

Compare with the alternating binomial sum evaluation Sum_{k = 0..2*n+1} (-1)^(n+k+1) * k^2 * binomial(2*n+1,k)^2. = (2*n+1)^2 * binomial(2*n,n) = A294486(n).

Crossrefs

Programs

  • Maple
    seq(add( (-1)^(n+k)*k^3*binomial(n,k)^2, k = 0..n ), n = 0..20);
  • PARI
    a(n) = (-1)^((n-1)*(n+2)/2) * n*((n+1)\2)^2 * binomial(n, n\2) \\ Winston de Greef, Mar 24 2023
    
  • Python
    from math import comb
    def A361719(n): return (-((m:=n>>1)+1)*n**2*comb(n-1,m) if n&2 else ((m:=n>>1)+1)*n**2*comb(n-1,m)) if n&1 else (((m:=n>>1)**3<<1)*comb(n,m) if n&2 else -((m:=n>>1)**3<<1)*comb(n,m)) # Chai Wah Wu, Mar 24 2023

Formula

a(n) = (-1)^((n-1)*(n+2)/2) * n*floor((n+1)/2)^2 * binomial(n, floor(n/2)) = (-1)^((n-1)*(n+2)/2) * n*floor((n+1)/2)^2 * A001405(n).
a(2*n) = (-1)^(n+1) * 2*n^3 * binomial(2*n,n).
a(2*n+1) = (-1)^n * (n+1)*(2*n+1)^2 * binomial(2*n,n).
a(n) = (-1)^(n+1) * n^2 * hypergeom([2, 1 - n, 1 - n], [1, 1], -1).
P-recursive: (2*n^2 - 5*n + 4)*(n - 2)*(n - 1)^3*a(n) = 2*n^2*(3*n - 5)*(n - 2)*a(n-1) - 4*n^2*(2*n^2 - n + 1)*(n - 1)^2*a(n-2) with a(0) = 0 and a(1) = 1.
5*Sum_{n >= 1} 1/a(2*n) = zeta(3), a result due to Markov (1890), rediscovered by Apéry (1979). - Peter Bala, Oct 24 2023
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