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 1-10 of 11 results. Next

A238010 Number A(n,k) of partitions of k^n into parts that are at most n; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 3, 1, 1, 0, 1, 5, 10, 1, 1, 0, 1, 9, 75, 64, 1, 1, 0, 1, 13, 374, 4410, 831, 1, 1, 0, 1, 19, 1365, 123464, 1366617, 26207, 1, 1, 0, 1, 25, 3997, 1736385, 393073019, 2559274110, 2239706, 1, 1
Offset: 0

Views

Author

Alois P. Heinz, Feb 16 2014

Keywords

Comments

In general, column k>=2 is asymptotic to k^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

Examples

			A(3,2) = 10: 332, 2222, 3221, 3311, 22211, 32111, 221111, 311111, 2111111, 11111111.
A(2,3) = 5: 22221, 222111, 2211111, 21111111, 111111111.
A(2,4) = 9: 22222222, 222222211, 2222221111, 22222111111, 222211111111, 2221111111111, 22111111111111, 211111111111111, 1111111111111111.
Square array A(n,k) begins:
  0, 0,   0,       0,         0,           0, ...
  1, 1,   1,       1,         1,           1, ...
  1, 1,   3,       5,         9,          13, ...
  1, 1,  10,      75,       374,        1365, ...
  1, 1,  64,    4410,    123464,     1736385, ...
  1, 1, 831, 1366617, 393073019, 33432635477, ...
		

Crossrefs

Rows n=0-2 give: A000004, A000012, A080827.
Main diagonal gives A238000.

Programs

  • Mathematica
    A[n_, k_] := SeriesCoefficient[Product[1/(1-x^j), {j, 1, n}], {x, 0, k^n}]; A[0, 0] = 0; Table[A[n-k, k], {n, 0, 9}, {k, n, 0, -1}] // Flatten (* Jean-François Alcover, Feb 17 2017 *)

Formula

A(n,k) = [x^(k^n)] Product_{j=1..n} 1/(1-x^j).

A237999 Number of partitions of 2^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 1, 2, 9, 119, 4935, 596763, 211517867, 224663223092, 734961197081208, 7614278809664610952, 256261752606028225485183, 28642174350851846128820426827, 10830277060032417592098008847162727, 14068379226083299071248895931891435683229
Offset: 0

Views

Author

Alois P. Heinz, Feb 16 2014

Keywords

Comments

From Gus Wiseman, May 31 2019: (Start)
Also the number of strict integer partitions of 2^n with n parts. For example, the a(1) = 1 through a(4) = 9 partitions are (A = 10):
(2) (31) (431) (6532)
(521) (6541)
(7432)
(7531)
(7621)
(8431)
(8521)
(9421)
(A321)
(End)

Examples

			a(1) = 1: 11.
a(2) = 1: 211.
a(3) = 2: 3221, 32111.
a(4) = 9: 433321, 443221, 4322221, 4332211, 4432111, 43222111, 43321111, 432211111, 4321111111.
		

Crossrefs

Programs

  • Mathematica
    a[n_] := SeriesCoefficient[Product[1/(1 - x^j), {j, 1, n}], {x, 0, 2^n - n*(n + 1)/2}];
    Table[an = a[n]; Print["a(", n, ") = ", an]; an, {n, 0, 15}] (* Jean-François Alcover, Aug 19 2018 *)

Formula

a(n) = [x^(2^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 2^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A238001 Number of partitions of n^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 1, 48, 109809, 32796849930, 2555847904495965819, 85962759806610904434664386174, 1841132100297745277187328924904656111127054, 34687813181057391872792859998288408847592250236051615502024
Offset: 0

Views

Author

Alois P. Heinz, Feb 16 2014

Keywords

Examples

			a(1) = 1: 1.
a(2) = 1: 211.
a(3) = 48: 3333333321, ..., 321111111111111111111111.
		

Crossrefs

Main diagonal of A238012.

Programs

  • Mathematica
    maxExponent = 50; a[0] = 0; a[1] = 1;
    a[n_] := Module[{}, aparts = List @@ (Product[1/(1 - x^j), {j, 1, n}] // Apart); cc = aparts + O[x]^maxExponent // CoefficientList[#, x]&; f[k_] = Total[FindSequenceFunction[#, k]& /@ cc]; f[n^n-n(n+1)/2 + 1] // Round];
    Table[an = a[n]; Print[n, " ", an]; an, {n, 0, 9}] (* Jean-François Alcover, Nov 15 2018 *)

Formula

a(n) = [x^(n^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ n^(n*(n-1)) / (n!*(n-1)!) ~ exp(2*n) * n^(n*(n-3)) / (2*Pi). - Vaclav Kotesovec, Jun 05 2015

A239168 Number of partitions of 9^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 40, 43923, 1956835062, 4219267293723828, 490589938553810921101750, 3299246284983094033572923631218500, 1347808520417651710823757078029174789058075682, 34687813181057391872792859998288408847592250236051615502024
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Crossrefs

Column k=9 of A238012.

Formula

a(n) = [x^(9^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 9^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A239162 Number of partitions of 3^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 4, 48, 3042, 1067474, 2215932130, 29012104252380, 2526293243761311036, 1525710603023191548743988, 6600334932211428773703751221040, 209705652574790086852527310591449309624, 49907101066058865036206450041083799915221352487
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Examples

			a(2) = 4: 22221, 222111, 2211111, 21111111.
		

Crossrefs

Column k=3 of A238012.

Programs

  • Mathematica
    maxExponent = 30; a[0] = 0; a[1] = 1;
    a[n_] := Module[{}, aparts = List @@ (Product[1/(1 - x^j), {j, 1, n}] // Apart); cc = aparts + O[x]^maxExponent // CoefficientList[#, x]&; f[k_] = Total[FindSequenceFunction[#, k]& /@ cc]; f[3^n - n(n+1)/2 + 1] // Round]; Table[an = a[n];
    Print[n, " ", an]; an, {n, 0, 12}] (* Jean-François Alcover, Nov 15 2018 *)

Formula

a(n) = [x^(3^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 3^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A239163 Number of partitions of 4^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 7, 310, 109809, 370702459, 13173778523786, 5303087097326728307, 25501946239758780918956349, 1523132187565775833398409415522245, 1163511401871888391788752975911167467265905, 11631778554448496258128131825307023131265496068454454
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Examples

			a(2) = 7: 222222211, 2222221111, 22222111111, 222211111111, 2221111111111, 22111111111111, 211111111111111.
		

Crossrefs

Column k=4 of A238012.

Programs

  • Mathematica
    maxExponent = 40; a[0] = 0; a[1] = 1;
    a[n_] := Module[{}, aparts = List @@ (Product[1/(1 - x^j), {j, 1, n}] // Apart); cc = aparts + O[x]^maxExponent // CoefficientList[#, x]&; f[k_] = Total[FindSequenceFunction[#, k]& /@ cc]; f[4^n-n(n+1)/2 + 1] // Round];
    Table[an = a[n]; Print[n, " ", an]; an, {n, 0, 11}] (* Jean-François Alcover, Nov 15 2018 *)

Formula

a(n) = [x^(4^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 4^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A239164 Number of partitions of 5^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 12, 1240, 1655004, 32796849930, 10743023668660275, 62590747974586286694030, 6826987264035710020018176749475, 14471606032117455546329821353159274382372, 613427607589897771307393494301176209875530879140211
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Examples

			a(2) = 12: 2222222222221, 22222222222111, 222222222211111, 2222222221111111, 22222222111111111, 222222211111111111, 2222221111111111111, 22222111111111111111, 222211111111111111111, 2221111111111111111111, 22111111111111111111111, 211111111111111111111111.
		

Crossrefs

Column k=5 of A238012.

Programs

  • Mathematica
    maxExponent = 45; a[0] = 0; a[1] = 1;
    a[n_] := Module[{}, aparts = List @@ (Product[1/(1 - x^j), {j, 1, n}] // Apart); cc = aparts + O[x]^maxExponent // CoefficientList[#, x]&; f[k_] = Total[FindSequenceFunction[#, k]& /@ cc];f[5^n - n(n+1)/2 + 1] // Round];
    Table[an = a[n]; Print[n, " ", an]; an, {n, 0, 10}] (* Jean-François Alcover, Nov 15 2018 *)

Formula

a(n) = [x^(5^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 5^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A239165 Number of partitions of 6^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 17, 3781, 14942231, 1264608203048, 2555847904495965819, 132574244496779071303074376, 185560862224740635595130202984468935, 7271076505438083132065943012753686950455454055, 8205115354631567886718289443554629632451344416164686337673
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Crossrefs

Column k=6 of A238012.

Programs

  • Mathematica
    maxExponent = 50; a[0] = 0; a[1] = 1;
    a[n_] := Module[{}, aparts = List @@ (Product[1/(1 - x^j), {j, 1, n}] // Apart); cc = aparts + O[x]^maxExponent // CoefficientList[#, x]&; f[k_] = Total[FindSequenceFunction[#, k]& /@ cc]; f[6^n-n(n+1)/2+1] // Round];
    Table[an = a[n]; Print[n, " ", an]; an, {n, 0, 10}] (* Jean-François Alcover, Nov 15 2018 *)

Formula

a(n) = [x^(6^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 6^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A239166 Number of partitions of 7^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 24, 9633, 95520600, 27656224652420, 260755601247189041231, 85962759806610904434664386174, 1041189281477724923668568740931602845066, 480588514551700434552887677121496205669535589365780, 8695551969224574889031840216144104978715552114947924501069394617
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Crossrefs

Column k=7 of A238012.

Formula

a(n) = [x^(7^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 7^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015

A239167 Number of partitions of 8^n into parts that are at most n with at least one part of each size.

Original entry on oeis.org

0, 1, 31, 21590, 475473009, 399953578562811, 14325140434481169064975, 23442235543128214521886383970201, 1841132100297745277187328924904656111127054, 7197719612276659958196058354497691622150052900765626132
Offset: 0

Views

Author

Alois P. Heinz, Mar 11 2014

Keywords

Crossrefs

Column k=8 of A238012.

Formula

a(n) = [x^(8^n-n*(n+1)/2)] Product_{j=1..n} 1/(1-x^j).
a(n) ~ 8^(n*(n-1)) / (n!*(n-1)!). - Vaclav Kotesovec, Jun 05 2015
Showing 1-10 of 11 results. Next