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 1-7 of 7 results.

A234043 a(n) = binomial(5*(n+1),4)/5, with n >= 0.

Original entry on oeis.org

1, 42, 273, 969, 2530, 5481, 10472, 18278, 29799, 46060, 68211, 97527, 135408, 183379, 243090, 316316, 404957, 511038, 636709, 784245, 956046, 1154637, 1382668, 1642914, 1938275, 2271776, 2646567, 3065923, 3533244, 4052055, 4626006, 5258872, 5954553, 6717074
Offset: 0

Views

Author

Wolfdieter Lang, Feb 24 2014

Keywords

Comments

Used as one of the 5-section parts of A234042.
The Fuss-Catalan numbers are Cat(d,k) = (1/(k*(d-1)+1))*binomial(k*d,k) and enumerate the (d+1)-gon partitions of a (k*(d-1)+2)-gon (cf. Whieldon and Schuetz link). a(n) = Cat(n,5) (Offset=1), so enumerates the (n+1)-gon partitions of a (5*(n-1)+2)-gon. Analogous series are A000326 (k=3) and A100157 (k=4). - Tom Copeland, Oct 05 2014

Crossrefs

Programs

  • Magma
    [Binomial(5*(n+1),4)/5: n in [0..40]]; // Vincenzo Librandi, Feb 26 2014
  • Mathematica
    CoefficientList[Series[(1 + 37 x + 73 x^2 + 14 x^3)/(1 - x)^5, {x, 0, 40}], x] (* Vincenzo Librandi, Feb 26 2014 *)

Formula

G.f: (1 + 37*x + 73*x^2 + 14*x^3)/(1-x)^5.
a(n) = A234042(5*n+1) for n >= 0.
a(n) = (n+1)*(5*n+2)*(5*n+3)*(5*n+4)/24.
From Amiram Eldar, Sep 20 2022: (Start)
Sum_{n>=0} 1/a(n) = 10*sqrt(5)*log(phi) + 5*log(5) - 2*sqrt(25-38/sqrt(5))*Pi, where phi is the golden ratio (A001622).
Sum_{n>=0} (-1)^n/a(n) = 4*sqrt(5)*log(phi) + 2*sqrt(26-38/sqrt(5))*Pi - 32*log(2). (End)

A362863 Centered hecatonicosachoral numbers.

Original entry on oeis.org

1, 1441, 11521, 44641, 122401, 273601, 534241, 947521, 1563841, 2440801, 3643201, 5243041, 7319521, 9959041, 13255201, 17308801, 22227841, 28127521, 35130241, 43365601, 52970401, 64088641, 76871521, 91477441, 108072001, 126828001, 147925441, 171551521, 197900641
Offset: 1

Views

Author

Léo Cymrot Cymbalista, May 06 2023

Keywords

Comments

A hecatonicosachoral number is a centered figurate number that represents a hecatonicosachoron, which is a four-dimensional regular polytope composed of 120 cells.
One of the 6 centered regular polichoral (centered pentachoral, centered hexadecachoral, centered octachoral, centered icositetrachoral, centered hexacosichoral and centered hecatonicosachoral) numbers.

Crossrefs

Cf. A005891 (2D), A005904 (3D), A006322, A151989.

Programs

  • Mathematica
    Table[300*n^4 - 600*n^3 + 420*n^2 - 120*n + 1, {n, 1, 100}]

Formula

a(n) = 300*n^4 - 600*n^3 + 420*n^2 - 120*n + 1.
a(n) = 1440*A006322(n-1) + 1 for n > 1.
a(n) = 288*(A151989(n-1)-1)/25 + 1.
G.f.: x*(1 + 1436*x + 4326*x^2 + 1436*x^3 + x^4)/(1 - x)^5. - Stefano Spezia, May 12 2023

A001512 a(n) = (5*n+1)*(5*n+2)*(5*n+3)*(5*n+4).

Original entry on oeis.org

24, 3024, 24024, 93024, 255024, 570024, 1113024, 1974024, 3258024, 5085024, 7590024, 10923024, 15249024, 20748024, 27615024, 36060024, 46308024, 58599024, 73188024, 90345024, 110355024, 133518024, 160149024, 190578024, 225150024, 264225024, 308178024
Offset: 0

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Author

Keywords

Crossrefs

Programs

Formula

G.f.: 24*( x^4 + 121*x^3 + 381*x^2 + 121*x + 1 )/( 1-x )^5. - Maksym Voznyy (voznyy(AT)mail.ru), Jul 26 2009 [corrected by Jaume Oliver Lafont, Sep 19 2009]
From Amiram Eldar, Sep 20 2022: (Start)
Sum_{n>=0} 1/a(n) = sqrt(10-22/sqrt(5))*Pi/30.
Sum_{n>=0} (-1)^n/a(n) = 4*log(2)/15 - 2*log(phi)/(3*sqrt(5)), where phi is the golden ratio (A001622). (End)

A238471 a(n) = binomial(5n+6, 4)/5 for n >= 0.

Original entry on oeis.org

3, 66, 364, 1197, 2990, 6293, 11781, 20254, 32637, 49980, 73458, 104371, 144144, 194327, 256595, 332748, 424711, 534534, 664392, 816585, 993538, 1197801, 1432049, 1699082, 2001825, 2343328, 2726766, 3155439, 3632772, 4162315, 4747743, 5392856, 6101579, 6877962
Offset: 0

Views

Author

Wolfdieter Lang, Feb 28 2014

Keywords

Comments

This sequence appears in the 5-section of A234042.

Crossrefs

Programs

  • Mathematica
    a[n_] := Binomial[5*n + 6, 4]/5; Array[a, 40, 0] (* Amiram Eldar, Sep 20 2022 *)

Formula

a(n) = binomial(5*n+6, 4)/5 = (5*n+6)*(5*n+3)*(5*n+4)*(n+1)/4! for n >= 0.
a(n) = A234042(5*n+2) for n >= 0.
a(n) = 3*b(n) + 51*b(n-1) + 64*b(n-2) + 7*b(n-3), with b(n) = binomial(n+4,4) = A000332(n) for n >= 0.
O.g.f.: (3 + 51*x + 64*x^2 + 7*x^3)/(1-x)^5.
Sum_{n>=0} 1/a(n) = 2*sqrt(5+2/sqrt(5))*Pi - 10*sqrt(5)*log(phi) - 15*log(5) + 20, where phi is the golden ratio (A001622). - Amiram Eldar, Sep 20 2022

A238472 a(n) = binomial(5*n+7, 4)/5 for n >= 0.

Original entry on oeis.org

7, 99, 476, 1463, 3510, 7192, 13209, 22386, 35673, 54145, 79002, 111569, 153296, 205758, 270655, 349812, 445179, 558831, 692968, 849915, 1032122, 1242164, 1482741, 1756678, 2066925, 2416557, 2808774, 3246901, 3734388, 4274810, 4871867, 5529384, 6251311, 7041723
Offset: 0

Views

Author

Wolfdieter Lang, Feb 28 2014

Keywords

Comments

This sequence appears in the 5-section of A234042.

Crossrefs

Programs

  • Mathematica
    a[n_] := Binomial[5*n + 7, 4]/5; Array[a, 40, 0] (* Amiram Eldar, Sep 20 2022 *)

Formula

a(n) = binomial(5*n+7, 4)/5 for n >= 0.
a(n) = A234042(5*n+3) for n >= 0.
a(n) = 7*b(n) + 64*b(n-1) + 51*b(n-2) + 3*b(n-3), with b(n) = binomial(n+4,4) = A000332(n) for n >= 0.
O.g.f.: (7 + 64*x + 51*x^2 + 3*x^3)/(1-x)^5.
Sum_{n>=0} 1/a(n) = 2*sqrt(5+2/sqrt(5))*Pi + 10*sqrt(5)*log(phi) + 15*log(5) - 50, where phi is the golden ratio (A001622). - Amiram Eldar, Sep 20 2022

A238473 a(n) = binomial(5*n+8, 4)/5 for n >= 0.

Original entry on oeis.org

14, 143, 612, 1771, 4095, 8184, 14763, 24682, 38916, 58565, 84854, 119133, 162877, 217686, 285285, 367524, 466378, 583947, 722456, 884255, 1071819, 1287748, 1534767, 1815726, 2133600, 2491489, 2892618, 3340337, 3838121, 4389570, 4998409, 5668488, 6403782, 7208391
Offset: 0

Views

Author

Wolfdieter Lang, Feb 28 2014

Keywords

Comments

This sequence appears in the 5-section of A234042.

Crossrefs

Programs

  • Mathematica
    a[n_] := Binomial[5*n + 8, 4]/5; Array[a, 40, 0] (* Amiram Eldar, Sep 20 2022 *)

Formula

a(n) = binomial(5*n+8, 4)/5 = (5*n+8)*(5*n+7)*(5*n+6)*(n+1)/4! for n >= 0.
a(n) = A234042(5*n+2) for n >= 0.
a(n) = 14*b(n) + 73*b(n-1) + 37*b(n-2) + b(n-3), with b(n) = binomial(n+4,4) = A000332(n) for n >= 0.
O.g.f.: (14 + 73*x + 37*x^2 + x^3)/(1-x)^5.
Sum_{n>=0} 1/a(n) = 110/3 - 2*sqrt(25 - 38/sqrt(5))*Pi - 10*sqrt(5)*log(phi) - 5*log(5), where phi is the golden ratio (A001622). - Amiram Eldar, Sep 20 2022

A205795 Sums of coefficients of polynomials from 5n-th moments of X ~ Hypergeometric(4m, 5m, m).

Original entry on oeis.org

24, 2880, 43545600, 5230697472000, 2432902008176640000, 3102242008666197196800000, 8841761993739701954543616000000, 49205466506600690141269768273920000000, 485663859076129603777149565235783270400000000, 7911522544013240381082219675638737768808448000000000
Offset: 1

Views

Author

John M. Campbell, Feb 09 2012

Keywords

Comments

See Maple code below for formula for such polynomials.

Examples

			The evaluation of sum(binomial(n, k)*binomial(4*n, k)*k^5, k = 0 .. n) involves the polynomial  256*n^5-640*n^3+400*n^2+108*n-100, the sum of the coefficients of which is 24 = a(1).
		

Crossrefs

Programs

  • Maple
    with(PolynomialTools);polyn:=w->simplify(Pi^2*sum(binomial(n,k)*binomial(4*n,k)*k^w,k=0..n)*5^w/3125^n*csc((1/5)*Pi)*csc((2/5)*Pi)*GAMMA(4*n)/GAMMA(n-(floor((w+1)/5)*5-2)/5)/GAMMA(n-(floor(w/5)*5-1)/5)/GAMMA(n-(floor((w+2)/5)*5-3)/5)/GAMMA(n-(floor((w+3)/5)*5-4)/5));coefl:=d->CoefficientList(expand(polyn(d)),n);seq(sum(coefl(5*h)[m],m=1..nops(coefl(5*h))),h=1..5);seq(simplify(12*5^(5*n-5)*GAMMA(n-4/5)*GAMMA(n-3/5)*GAMMA(n-2/5)*GAMMA(n-1/5)*(cos((2/5)*Pi)+cos((1/5)*Pi))/Pi^2),n=1..5);

Formula

a(n) = 120*A151989(n-2)*a(n-1), with a(1)=24.
a(n) = 12*5^(5*n-5)*GAMMA(n-4/5)*GAMMA(n-3/5)*GAMMA(n-2/5)*GAMMA(n-1/5)*(cos((2/5)*Pi)+cos((1/5)*Pi))/Pi^2.
Showing 1-7 of 7 results.