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.

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A336214 a(n) = Sum_{k=0..n} k^n * binomial(n,k)^n, with a(0)=1.

Original entry on oeis.org

1, 1, 8, 270, 41984, 30706250, 94770093312, 1336016204844832, 76829717664330940416, 19838680914222199482800274, 20521247958509575370600000000000, 94285013320530947020636486516362047300, 1715947732437668013396578734960052732361179136
Offset: 0

Views

Author

Vaclav Kotesovec, Jul 12 2020

Keywords

Crossrefs

Programs

  • Mathematica
    Flatten[{1, Table[Sum[k^n*Binomial[n, k]^n, {k, 1, n}], {n, 1, 15}]}]
  • PARI
    a(n) = if (n==0, 1, sum(k=0, n, k^n * binomial(n,k)^n)); \\ Michel Marcus, Jul 13 2020

Formula

a(n) ~ c * exp(-1/4) * 2^(n^2 - n/2) * n^(n/2) / Pi^(n/2), where c = Sum_{k = -infinity..infinity} exp(-2*k*(k-1)) = exp(1/2) * sqrt(Pi/2) * EllipticTheta(3, -Pi/2, exp(-Pi^2/2)) = 2.036643566277677716389243890291939003151565... if n is even and c = Sum_{k = -infinity..infinity} exp(-2*k^2 + 1/2) = exp(1/2) * EllipticTheta(3, 0, exp(-2)) = 2.096087809957308346119920713317351288828811... if n is odd.
a(n) = n^n * A328812(n-1) for n > 0. - Seiichi Manyama, Jul 15 2020

A209427 T(n,k) = binomial(n,k)^n.

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 27, 27, 1, 1, 256, 1296, 256, 1, 1, 3125, 100000, 100000, 3125, 1, 1, 46656, 11390625, 64000000, 11390625, 46656, 1, 1, 823543, 1801088541, 64339296875, 64339296875, 1801088541, 823543, 1, 1, 16777216, 377801998336, 96717311574016, 576480100000000, 96717311574016, 377801998336, 16777216, 1
Offset: 0

Views

Author

Paul D. Hanna, Mar 08 2012

Keywords

Comments

Row sums equals A167010.
Column 1 forms A000312.
Antidiagonal sums form A209428.

Examples

			This triangle begins:
1;
1, 1;
1, 4, 1;
1, 27, 27, 1;
1, 256, 1296, 256, 1;
1, 3125, 100000, 100000, 3125, 1;
1, 46656, 11390625, 64000000, 11390625, 46656, 1;
1, 823543, 1801088541, 64339296875, 64339296875, 1801088541, 823543, 1;
1, 16777216, 377801998336, 96717311574016, 576480100000000, 96717311574016, 377801998336, 16777216, 1; ...
		

Crossrefs

Cf. A167010 (row sums), A000312 (column 1), A209428.

Programs

  • Mathematica
    Table[Binomial[n,k]^n, {n,0,10}, {k,0,n}]// Flatten (* G. C. Greubel, Jan 03 2018 *)
  • PARI
    {T(n,k)=binomial(n,k)^n}
    for(n=0,10,for(k=0,n,print1(T(n,k),","));print(""))

A336202 a(n) = Sum_{k=0..n} (-n)^k * binomial(n,k)^n.

Original entry on oeis.org

1, 0, -3, 136, 3585, -8065624, 985282165, 102324513620736, -758462117693095935, -310124007268556369914448, 59000420766060452235999162501, 231739512209034254162941881236647760, -948238573709799908746228205852168505192191, -43263440520748047736633474769642007589423961473152
Offset: 0

Views

Author

Seiichi Manyama, Jul 11 2020

Keywords

Crossrefs

Main diagonal of A336201.

Programs

  • Mathematica
    a[n_] := Sum[If[n == k == 0, 1, (-n)^k] * Binomial[n, k]^n, {k, 0, n}]; Array[a, 14, 0] (* Amiram Eldar, May 01 2021 *)
  • PARI
    {a(n) = sum(k=0, n, (-n)^k*binomial(n, k)^n)}

A336212 a(n) = Sum_{k=0..n} 3^k * binomial(n,k)^n.

Original entry on oeis.org

1, 4, 22, 352, 19426, 3862744, 2764634356, 7403121210496, 73087416841865890, 2751096296949421766824, 387442256655054793494004132, 210421903024207931092658380560256, 431805731803048897945138363105712865124, 3443300668674111298036287560913860498279204224
Offset: 0

Views

Author

Vaclav Kotesovec, Jul 12 2020

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[3^k * Binomial[n, k]^n, {k, 0, n}], {n, 0, 15}]
  • PARI
    {a(n) = sum(k=0, n, 3^k*binomial(n, k)^n)} \\ Seiichi Manyama, Jul 13 2020

Formula

a(n) ~ c * exp(-1/4) * 2^(n^2 + n/2) * (3/(Pi*n))^(n/2), where c = Sum_{k = -infinity..infinity} 3^k * exp(-2*k^2) = 1.4541744598397064657680975624481... if n is even and c = Sum_{k = -infinity..infinity} 3^(k + 1/2) * exp(-2*(k + 1/2)^2) = 1.4606428581939532945566671970305... if n is odd.

A336270 a(n) = Sum_{k=0..n} Sum_{j=0..k} (binomial(n,k) * binomial(k,j))^n.

Original entry on oeis.org

1, 3, 15, 381, 67635, 83118753, 813824623689, 58040410068847251, 32150480245981639533315, 154935057570894645075940703673, 5474671509704049919709361235659936825, 1600436120524545216094358662984789029130593831
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 15 2020

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[Sum[(Binomial[n, k] Binomial[k, j])^n, {j, 0, k}], {k, 0, n}], {n, 0, 11}]
    Table[(n!)^n SeriesCoefficient[Sum[x^k/(k!)^n, {k, 0, n}]^3, {x, 0, n}], {n, 0, 11}]
  • PARI
    a(n) = sum(k=0, n, sum(j=0, k, (binomial(n,k) * binomial(k,j))^n)); \\ Michel Marcus, Jul 16 2020

Formula

a(n) = (n!)^n * [x^n] (Sum_{k>=0} x^k / (k!)^n)^3.

A328810 a(n) = Sum_{i=0..n} binomial(n,i)*Sum_{j=0..i} binomial(i,j)^n.

Original entry on oeis.org

1, 3, 11, 93, 2583, 260613, 99915029, 144072750195, 808177412109895, 16892305881120020613, 1388286655114683125139201, 423109739462061163278604529475, 511885816860737850466697173188711669, 2296554708428991868313593456071099604464483
Offset: 0

Views

Author

Seiichi Manyama, Oct 28 2019

Keywords

Crossrefs

Main diagonal of A328807.

Programs

  • Mathematica
    Table[Sum[Binomial[n, i]*Sum[Binomial[i, j]^n, {j, 0, i}], {i, 0, n}], {n, 0, 15}] (* Vaclav Kotesovec, Oct 28 2019 *)
  • PARI
    {a(n) = sum(i=0, n, binomial(n, i)*sum(j=0, i, binomial(i, j)^n))}

Formula

a(n) ~ A167010(n). - Vaclav Kotesovec, Oct 28 2019

A328811 a(n) = Sum_{i=0..n} (-1)^(n-i)*binomial(n,i)*Sum_{j=0..i} binomial(i,j)^n.

Original entry on oeis.org

1, 1, 3, 31, 1255, 161671, 75481581, 121338954577, 734884394666535, 15970479086714049751, 1347242827078365957146473, 415839472158527880691583531617, 507266883682599825619985300960971525, 2284735689605775548174387143718048664963601
Offset: 0

Views

Author

Seiichi Manyama, Oct 28 2019

Keywords

Crossrefs

Main diagonal of A328747.

Programs

  • Mathematica
    Table[Sum[(-1)^(n-i)*Binomial[n, i]*Sum[Binomial[i, j]^n, {j, 0, i}], {i, 0, n}], {n, 0, 15}] (* Vaclav Kotesovec, Oct 28 2019 *)
  • PARI
    {a(n) = sum(i=0, n, (-1)^(n-i)*binomial(n, i)*sum(j=0, i, binomial(i, j)^n))}

Formula

a(n) ~ A167010(n). - Vaclav Kotesovec, Oct 28 2019

A336213 a(n) = Sum_{k=0..n} k^k * binomial(n,k)^n, with a(0)=1.

Original entry on oeis.org

1, 2, 9, 163, 12609, 3906251, 4835455813, 23882051929709, 470073929716006913, 36867039626275056203923, 11562789460238169439667262501, 14393917436542502296957220221339601, 72060131612303615870363237649174605005057, 1424448870088911493303605765206905153730451241313
Offset: 0

Views

Author

Vaclav Kotesovec, Jul 12 2020

Keywords

Crossrefs

Programs

  • Mathematica
    Table[1 + Sum[k^k * Binomial[n, k]^n, {k, 1, n}], {n, 0, 15}]
  • PARI
    a(n) = if (n==0, 1, sum(k=0, n, k^k * binomial(n,k)^n)); \\ Michel Marcus, Jul 13 2020

Formula

Let f(n) = exp(-1/4) * QPochhammer(exp(-4)) * 2^(n^2 - 1/4) * exp((3*log(n)^2 + 3*log(2)^2 + Pi^2 - 1)/24) * n^((1 - log(2))/4) / Pi^(n/2). For sufficiently large n 0.985... < a(n)/f(n) < 1.015...
a(n) ~ exp(-1/4) * QPochhammer(exp(-4)) * QPochhammer(-n*exp(-1)/2, exp(-4)) * 2^(n^2) / Pi^(n/2) if n is even and a(n) ~ exp(-1/4) * QPochhammer(exp(-4)) * QPochhammer(-n*exp(-3)/2, exp(-4)) * sqrt(n) * 2^(n^2 - 1/2) / Pi^(n/2) if n is odd.

A295611 a(n) = Sum_{k=0..n} (-1)^k*binomial(n,k)^k.

Original entry on oeis.org

1, 0, 0, 6, -30, -280, 35070, -2508268, -47103462, 241470400824, -256752145545390, 128291714550379292, 2203924344437376054780, -37693423679943326954848176, 485163732930867224220253809178, 27101025121379607823580070619517816
Offset: 0

Views

Author

Ilya Gutkovskiy, Nov 24 2017

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[(-1)^k Binomial[n, k]^k, {k, 0, n}], {n, 0, 15}]
    Table[Sum[(-1)^k (n!/(k! (n - k)!))^k, {k, 0, n}], {n, 0, 15}]
  • PARI
    a(n) = sum(k=0, n, (-1)^k*binomial(n,k)^k); \\ Michel Marcus, Nov 25 2017

Formula

a(n) = Sum_{k=0..n} (-1)^k*A219206(n,k).
Limit n->infinity |a(n)|^(1/n^2) = r^(r^2/(1-2*r)) = 1.533628065110458582053143..., where r = A220359 = 0.70350607643066243096929661621777... is the real root of the equation (1-r)^(2*r-1) = r^(2*r). - Vaclav Kotesovec, Nov 25 2017

A336829 a(n) = Sum_{k=0..n} binomial(n+k,k)^n.

Original entry on oeis.org

1, 3, 46, 9065, 25561876, 1048567813062, 632156164654144530, 5652307059542612442465921, 755658094192422806457805924637704, 1521188219372604726826961340683399629967888, 46388428590466766659538640978460161019178279424832676
Offset: 0

Views

Author

Ilya Gutkovskiy, Aug 05 2020

Keywords

Crossrefs

Programs

  • Magma
    [(&+[Binomial(2*n-j,n)^n: j in [0..n]]): n in [0..20]]; // G. C. Greubel, Aug 31 2022
    
  • Mathematica
    Table[Sum[Binomial[n + k, k]^n, {k, 0, n}], {n, 0, 10}]
  • PARI
    a(n) = sum(k=0, n, binomial(n+k, k)^n); \\ Michel Marcus, Aug 05 2020
    
  • SageMath
    def A336829(n): return sum(binomial(2*n-j, n)^n for j in (0..n))
    [A336829(n) for n in (0..20)] # G. C. Greubel, Aug 31 2022

Formula

a(n) ~ exp(-1/8) * 2^(2*n^2) / (Pi*n)^(n/2). - Vaclav Kotesovec, Jul 10 2021
Previous Showing 11-20 of 23 results. Next