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.

Previous Showing 31-37 of 37 results.

A263070 Number of lattice paths from {n}^10 to {0}^10 using steps that decrement one or more components by one.

Original entry on oeis.org

1, 102247563, 1843200116875263613, 93777824804632275267836362863, 7581761490297442738124283591348762605121, 797656368265147949572521540584234236944835806750363, 99479717242433942914309980793245660313479486272546475327799069
Offset: 0

Views

Author

Alois P. Heinz, Oct 08 2015

Keywords

Crossrefs

Column k=10 of A262809.

Programs

  • Mathematica
    With[{k = 10}, Table[Sum[Sum[(-1)^i*Binomial[j, i]*Binomial[j - i, n]^k, {i, 0, j}], {j, 0, k*n}], {n, 0, 10}]] (* Vaclav Kotesovec, Mar 22 2016 *)

Formula

a(n) ~ sqrt(c) * d^n / (Pi*n)^(9/2), where d = 275651917450.670923828699577660562035773700532729... and c = 0.02031773288889520997973589484779079409621454... . - Vaclav Kotesovec, Mar 23 2016

A263071 Number of lattice paths from {9}^n to {0}^n using steps that decrement one or more components by one.

Original entry on oeis.org

1, 1, 1462563, 191731486403293, 496505991344667030490635, 12024609569670508078686022988554381, 1742079663955078309800553960117733249663480043, 1121241285685659360225420876424590015281785102622410968973
Offset: 0

Views

Author

Alois P. Heinz, Oct 08 2015

Keywords

Crossrefs

Row n=9 of A262809.

Programs

  • Mathematica
    With[{r = 9}, Flatten[{1, Table[Sum[Sum[(-1)^i*Binomial[j, i]*Binomial[j - i, r]^k, {i, 0, j}], {j, 0, k*r}], {k, 1, 10}]}]] (* Vaclav Kotesovec, Mar 22 2016 *)

Formula

a(n) ~ 3*sqrt(Pi) * (9^8/8!)^n * n^(9*n+1/2) / (2^(9/2) * exp(9*n) * (log(2))^(9*n+1)). - Vaclav Kotesovec, Mar 23 2016

A263072 Number of lattice paths from {10}^n to {0}^n using steps that decrement one or more components by one.

Original entry on oeis.org

1, 1, 8097453, 9850349744182729, 331910222316215755702672557, 134565509066155510620216211257550349401, 399017534874989738901076297624977315332337599285373, 6213239693876579408708842528154872834110410698303331900339282569
Offset: 0

Views

Author

Alois P. Heinz, Oct 08 2015

Keywords

Comments

In general, row r > 0 of A262809 is asymptotic to sqrt(r*Pi) * (r^(r-1)/(r-1)!)^n * n^(r*n+1/2) / (2^(r/2) * exp(r*n) * (log(2))^(r*n+1)). - Vaclav Kotesovec, Mar 23 2016

Crossrefs

Row n=10 of A262809.

Programs

  • Mathematica
    With[{r = 10}, Flatten[{1, Table[Sum[Sum[(-1)^i*Binomial[j, i]*Binomial[j - i, r]^k, {i, 0, j}], {j, 0, k*r}], {k, 1, 10}]}]] (* Vaclav Kotesovec, Mar 22 2016 *)

Formula

a(n) ~ sqrt(10*Pi) * (10^9/9!)^n * n^(10*n+1/2) / (32 * exp(10*n) * (log(2))^(10*n+1)). - Vaclav Kotesovec, Mar 23 2016

A331637 Number of binary matrices with nonzero rows, a total of n ones and each column with the same number of ones.

Original entry on oeis.org

1, 4, 14, 89, 542, 5156, 47294, 570074, 7103343, 104493608, 1622632574, 28411638982, 526858348382, 10699857854372, 230297862127828, 5330284144906443, 130370767029135902, 3390229775073259800, 92801587319328411134, 2679531116538955252338
Offset: 1

Views

Author

Andrew Howroyd, Jan 23 2020

Keywords

Examples

			The a(2) = 4 matrices are:
  [1]  [1 0]  [0 1]  [1 1]
  [1]  [0 1]  [1 0]
		

Crossrefs

Cf. A262809.

Formula

a(n) = Sum_{d|n} A262809(n/d, d).

A384351 Expansion of Product_{k>=1} 1/(1 - k*(k+1)/2 * x)^((1/2)^(k+2)).

Original entry on oeis.org

1, 1, 7, 143, 6140, 455828, 51947988, 8414718996, 1836791273514, 519582028795210, 184852108308617398, 80776494267416227078, 42529172631705836804876, 26553065315757661351020284, 19397441882229095276127402500, 16390942374821715002096327774628
Offset: 0

Views

Author

Seiichi Manyama, May 27 2025

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Exp[Sum[Sum[Sum[(-1)^j*Binomial[i, j]*((i - j)*(i - j - 1)/2)^k, {j, 0, i}], {i, 0, 2 k}]*x^k/k, {k, 1, nmax}]], {x, 0, nmax}], x] (* Vaclav Kotesovec, May 29 2025 *)
  • PARI
    a262809(n, k) = sum(i=0, k*n, sum(j=0, i, (-1)^j*binomial(i, j)*binomial(i-j, n)^k));
    my(N=20, x='x+O('x^N)); Vec(exp(sum(k=1, N, a262809(2, k)*x^k/k)))

Formula

G.f.: exp(Sum_{k>=1} A055203(k) * x^k/k).
a(n) ~ sqrt(Pi) * 2^(n - 1/2) * n^(2*n - 1/2) / (exp(2*n) * log(2)^(2*n+1)). - Vaclav Kotesovec, May 29 2025

A384352 Expansion of Product_{k>=1} 1/(1 - k*(k+1)*(k+2)/6 * x)^((1/2)^(k+3)).

Original entry on oeis.org

1, 1, 32, 5392, 2676188, 2930633692, 5993325199448, 20540879727692152, 109337218761743017718, 854254522610491562826582, 9378640254148405369808277352, 139752461092050444767050922501096, 2747716352285121538660626991038190636, 69628008338488529846443753577404293410060
Offset: 0

Views

Author

Seiichi Manyama, May 27 2025

Keywords

Crossrefs

Programs

  • PARI
    a262809(n, k) = sum(i=0, k*n, sum(j=0, i, (-1)^j*binomial(i, j)*binomial(i-j, n)^k));
    my(N=20, x='x+O('x^N)); Vec(exp(sum(k=1, N, a262809(3, k)*x^k/k)))

Formula

G.f.: exp(Sum_{k>=1} A062208(k) * x^k/k).

A384353 Expansion of Product_{k>=1} 1/(1 - k*(k+1)*(k+2)*(k+3)/24 * x)^((1/2)^(k+4)).

Original entry on oeis.org

1, 1, 161, 233201, 1388333781, 23407417517205, 900363695229160325, 68584682130559722233525, 9362104205577409136806214275, 2125938144923623062958782871506275, 758178276483321320080629434392636915075, 405630344408921348237973282862682052175313075
Offset: 0

Views

Author

Seiichi Manyama, May 27 2025

Keywords

Crossrefs

Programs

  • PARI
    a262809(n, k) = sum(i=0, k*n, sum(j=0, i, (-1)^j*binomial(i, j)*binomial(i-j, n)^k));
    my(N=20, x='x+O('x^N)); Vec(exp(sum(k=1, N, a262809(4, k)*x^k/k)))

Formula

G.f.: exp(Sum_{k>=1} A062205(k) * x^k/k).
Previous Showing 31-37 of 37 results.