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 1-6 of 6 results.

A294212 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of e.g.f.: exp(Product_{j=1..n} 1/(1-x^j) - 1).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 1, 3, 0, 1, 1, 5, 13, 0, 1, 1, 5, 25, 73, 0, 1, 1, 5, 31, 193, 501, 0, 1, 1, 5, 31, 241, 1601, 4051, 0, 1, 1, 5, 31, 265, 2261, 16741, 37633, 0, 1, 1, 5, 31, 265, 2501, 25501, 190345, 394353, 0, 1, 1, 5, 31, 265, 2621, 29461, 319915, 2509025
Offset: 0

Views

Author

Seiichi Manyama, Oct 25 2017

Keywords

Examples

			Square array B(j,k) begins:
   1,   1,    1,    1,    1, ...
   0,   1,    1,    1,    1, ...
   0,   1,    2,    2,    2, ...
   0,   1,    2,    3,    3, ...
   0,   1,    3,    4,    5, ...
   0,   1,    3,    5,    6, ...
Square array A(n,k) begins:
   1,   1,    1,    1,    1, ...
   0,   1,    1,    1,    1, ...
   0,   3,    5,    5,    5, ...
   0,  13,   25,   31,   31, ...
   0,  73,  193,  241,  265, ...
   0, 501, 1601, 2261, 2501, ...
		

Crossrefs

Columns k=0..5 give A000007, A000262, A294213, A294214, A294215, A294216.
Rows n=0 gives A000012.
Main diagonal gives A058892.

Formula

B(j,k) is the coefficient of Product_{i=1..k} 1/(1-x^i).
A(0,k) = 1 and A(n,k) = (n-1)! * Sum_{j=1..n} j*B(j,k)*A(n-j,k)/(n-j)! for n > 0.

A294261 E.g.f.: exp(Sum_{n>=1} A081362(n)*x^n).

Original entry on oeis.org

1, -1, 1, -7, 49, -301, 2281, -21211, 260737, -3254329, 41086801, -589336111, 9851907121, -170708882917, 3060177746809, -60544788499651, 1298663388032641, -28777111728560881, 665551703689032097, -16413980708818538839, 428253175770218766001
Offset: 0

Views

Author

Seiichi Manyama, Oct 26 2017

Keywords

Crossrefs

Main diagonal of A294289.

Formula

a(0) = 1 and a(n) = (n-1)! * Sum_{k=1..n} k*A081362(k)*a(n-k)/(n-k)! for n > 0.

A294291 E.g.f.: exp(1/((1+x)*(1+x^2)*(1+x^3)) - 1).

Original entry on oeis.org

1, -1, 1, -7, 73, -421, 2641, -32131, 403537, -4527433, 57723841, -902025631, 15198774361, -258241785517, 4617616213393, -92675891536411, 2008139896617121, -44077045165245841, 1009237851013130497, -25134834585692446903, 658430145120963410281
Offset: 0

Views

Author

Seiichi Manyama, Oct 27 2017

Keywords

Crossrefs

Column k=3 of A294289.

Programs

  • PARI
    N=66; x='x+O('x^N); Vec(serlaplace(exp(1/((1+x)*(1+x^2)*(1+x^3))-1)))

A294292 Expansion of e.g.f. exp(1/((1+x)*(1+x^2)*(1+x^3)*(1+x^4)) - 1).

Original entry on oeis.org

1, -1, 1, -7, 49, -181, 1561, -18691, 173377, -2150569, 28355761, -356432671, 5780298481, -95621235997, 1506345546889, -29605056916891, 624987953076481, -12495650070557521, 277892162543608417, -6701525504691986359, 160540685175500028721
Offset: 0

Views

Author

Seiichi Manyama, Oct 27 2017

Keywords

Crossrefs

Column k=4 of A294289.

Programs

  • PARI
    N=66; x='x+O('x^N); Vec(serlaplace(exp(1/((1+x)*(1+x^2)*(1+x^3)*(1+x^4))-1)))

Formula

E.g.f.: exp(1/((1+x)*(1+x^2)*(1+x^3)*(1+x^4)) - 1).

A294290 E.g.f.: exp(1/((1+x)*(1+x^2)) - 1).

Original entry on oeis.org

1, -1, 1, -1, 25, -241, 1081, -3361, 68881, -1288225, 11828881, -69917761, 1347298921, -36402297361, 533785676425, -4949573821921, 96936811739041, -3274354780495681, 67608887254849441, -885780921100074625, 18450482854023522361, -718444927697360335921
Offset: 0

Views

Author

Seiichi Manyama, Oct 27 2017

Keywords

Crossrefs

Column k=2 of A294289.

Programs

  • PARI
    N=66; x='x+O('x^N); Vec(serlaplace(exp(1/((1+x)*(1+x^2))-1)))

A294293 E.g.f.: exp(1/((1+x)*(1+x^2)*(1+x^3)*(1+x^4)*(1+x^5)) - 1).

Original entry on oeis.org

1, -1, 1, -7, 49, -301, 3001, -26251, 280897, -4040569, 52124401, -749335951, 12646748401, -215856019237, 4053285942889, -82462867482451, 1728838444704001, -38850070313151601, 922947645744036577, -22864122050534606359, 599150979583749111601
Offset: 0

Views

Author

Seiichi Manyama, Oct 27 2017

Keywords

Crossrefs

Column k=5 of A294289.

Programs

  • PARI
    N=66; x='x+O('x^N); Vec(serlaplace(exp(1/((1+x)*(1+x^2)*(1+x^3)*(1+x^4)*(1+x^5))-1)))
Showing 1-6 of 6 results.