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 21-25 of 25 results.

A268850 Number of sequences with 7 copies each of 1,2,...,n and longest increasing subsequence of length n.

Original entry on oeis.org

1, 1, 3431, 397222288, 460827731023773, 2931247600219365331976, 70803267480031877368227941803, 5078529731893937404909347067888886466, 909546798992441266072332791609067485208949369, 358281333933096129012031117609647623312585201668494007
Offset: 0

Views

Author

Alois P. Heinz, Feb 14 2016

Keywords

Crossrefs

Row n=7 of A047909.

Programs

  • Mathematica
    Table[Sum[Sum[Sum[Sum[Sum[Sum[k!/(i1!*i2!*i3!*i4!*i5!*i6!*(k - i1 - i2 - i3 - i4 - i5 - i6)!)*(7*k)!/(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*(k - i1 - i2 - i3 - i4 - i5 - i6))!*(-1)^(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*(k - i1 - i2 - i3 - i4 - i5 - i6) - k)/(720^i1*120^i2*24^i3*6^i4*2^i5), {i6, 0, k - i1 - i2 - i3 - i4 - i5}], {i5, 0, k - i1 - i2 - i3 - i4}], {i4, 0, k - i1 - i2 - i3}], {i3, 0, k - i1 - i2}], {i2, 0, k - i1}], {i1, 0, k}], {k, 0, 10}] (* Vaclav Kotesovec, Mar 02 2016, after Horton and Kurn *)

Formula

a(n) ~ sqrt(7) * (7^7/6!)^n * n^(6*n) / exp(6*(n+1)). - Vaclav Kotesovec, Mar 03 2016

A268851 Number of sequences with 8 copies each of 1,2,...,n and longest increasing subsequence of length n.

Original entry on oeis.org

1, 1, 12869, 9450343019, 98540942707986273, 7370846583668954571029069, 2612508237897293571677286548812861, 3315159778348807570604149155371730111763599, 12324197596430667064913735085330208112438377122058241
Offset: 0

Views

Author

Alois P. Heinz, Feb 14 2016

Keywords

Crossrefs

Row n=8 of A047909.

Programs

  • Mathematica
    Table[Sum[Sum[Sum[Sum[Sum[Sum[Sum[k!/(i1!*i2!*i3!*i4!*i5!*i6!*i7!*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7)!)*(8*k)!/(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*i7 + 8*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7))!*(-1)^(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*i7 + 8*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7) - k)/(5040^i1 * 720^i2 * 120^i3 * 24^i4 * 6^i5 * 2^i6), {i7, 0, k - i1 - i2 - i3 - i4 - i5 - i6}], {i6, 0, k - i1 - i2 - i3 - i4 - i5}], {i5, 0, k - i1 - i2 - i3 - i4}], {i4, 0, k - i1 - i2 - i3}], {i3, 0, k - i1 - i2}], {i2, 0, k - i1}], {i1, 0, k}], {k, 0, 10}] (* Vaclav Kotesovec, Mar 02 2016, after Horton and Kurn *)

Formula

a(n) ~ sqrt(8) * (8^8/7!)^n * n^(7*n) / exp(7*(n+1)). - Vaclav Kotesovec, Mar 03 2016

A268852 Number of sequences with 9 copies each of 1,2,...,n and longest increasing subsequence of length n.

Original entry on oeis.org

1, 1, 48619, 227749730869, 21364658238692907265, 18683332440278067962764855531, 96042041352156959435669839199503441435, 2124172213523649116114190361767338538457819064671, 161347197004751609388708454579308609212572710243373701247489
Offset: 0

Views

Author

Alois P. Heinz, Feb 14 2016

Keywords

Crossrefs

Row n=9 of A047909.

Programs

  • Mathematica
    Table[Sum[Sum[Sum[Sum[Sum[Sum[Sum[Sum[k!/(i1!*i2!*i3!*i4!*i5!*i6!*i7!*i8!*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8)!)*(9*k)!/(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*i7 + 8*i8 + 9*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8))!*(-1)^(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*i7 + 8*i8 + 9*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8) - k)/(8!^i1 * 7!^i2 * 6!^i3 * 5!^i4 * 4!^i5 * 3!^i6 * 2!^i7), {i8, 0, k - i1 - i2 - i3 - i4 - i5 - i6 - i7}], {i7, 0, k - i1 - i2 - i3 - i4 - i5 - i6}], {i6, 0, k - i1 - i2 - i3 - i4 - i5}], {i5, 0, k - i1 - i2 - i3 - i4}], {i4, 0, k - i1 - i2 - i3}], {i3, 0, k - i1 - i2}], {i2, 0, k - i1}], {i1, 0, k}], {k, 0, 10}] (* Vaclav Kotesovec, Mar 02 2016, after Horton and Kurn *)

Formula

a(n) ~ 3 * (9^9/8!)^n * n^(8*n) / exp(8*(n+1)). - Vaclav Kotesovec, Mar 03 2016

A268853 Number of sequences with 10 copies each of 1,2,...,n and longest increasing subsequence of length n.

Original entry on oeis.org

1, 1, 184755, 5549991941777, 4697818999010952011441, 47964531978782851644184417448714, 3553102771891168237056005934820411063204249, 1355554085495648757684163048897568469564674091083870680, 2077847308887546704733072843165544143697549966176523511722695300153
Offset: 0

Views

Author

Alois P. Heinz, Feb 14 2016

Keywords

Crossrefs

Row n=10 of A047909.

Programs

  • Mathematica
    Table[Sum[Sum[Sum[Sum[Sum[Sum[Sum[Sum[Sum[k!/(i1!*i2!*i3!*i4!*i5!*i6!* i7!*i8!*i9!*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8 - i9)!)*(10*k)!/(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*i7 + 8*i8 + 9*i9 + 10*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8 - i9))!*(-1)^(i1 + 2*i2 + 3*i3 + 4*i4 + 5*i5 + 6*i6 + 7*i7 + 8*i8 + 9*i9 + 10*(k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8 - i9) - k)/(9!^i1 * 8!^i2 * 7!^i3 * 6!^i4 * 5!^i5 * 4!^i6 * 3!^i7 * 2!^i8), {i9, 0, k - i1 - i2 - i3 - i4 - i5 - i6 - i7 - i8}], {i8, 0, k - i1 - i2 - i3 - i4 - i5 - i6 - i7}], {i7, 0, k - i1 - i2 - i3 - i4 - i5 - i6}], {i6, 0, k - i1 - i2 - i3 - i4 - i5}], {i5, 0, k - i1 - i2 - i3 - i4}], {i4, 0, k - i1 - i2 - i3}], {i3, 0, k - i1 - i2}], {i2, 0, k - i1}], {i1, 0, k}], {k, 0, 10}] (* Vaclav Kotesovec, Mar 02 2016, after Horton and Kurn *)

Formula

a(n) ~ sqrt(10) * (10^10/9!)^n * n^(9*n) / exp(9*(n+1)). - Vaclav Kotesovec, Mar 03 2016

A268667 Number of sequences with j copies of j for each j in {1,2,...,n} and longest increasing subsequence of length n.

Original entry on oeis.org

1, 1, 2, 26, 3511, 6742796, 233249911607, 175703195017370516, 3377940832101159287907151, 1899957346851645870857879683505890, 35246706696124014829643459097288501560957174, 23998872279553738609365779286317516184675391844037227392
Offset: 0

Views

Author

Alois P. Heinz, Feb 10 2016

Keywords

Comments

Sequences counted by a(n) have length A000217(n) and element sum A000330(n).

Examples

			a(2) = 2: 122, 212.
a(3) = 26: 122333, 123233, 123323, 123332, 132233, 132323, 132332, 133223, 133232, 212333, 213233, 213323, 231233, 231323, 233123, 312233, 312323, 312332, 313223, 313232, 321233, 321323, 323123, 331223, 331232, 332123.
		

Crossrefs

Programs

  • Maple
    g:= proc(l) option remember; (n-> f(l[1..nops(l)-1])*
          binomial(n-1, l[-1]-1)+ add(f(sort(subsop(j=l[j]
          -1, l))), j=1..nops(l)-1))(add(i, i=l))
        end:
    f:= l-> (n-> `if`(n<2 or l[-1]=1, 1, `if`(l[1]=0, 0, `if`(
             n=2, binomial(l[1]+l[2], l[1])-1, g(l)))))(nops(l)):
    a:= n-> f([$1..n]):
    seq(a(n), n=0..8);
  • Mathematica
    g[l_] := g[l] = Function[n, f[Most[l]]*Binomial[n-1, l[[-1]]-1] + Sum[f[ Sort[ ReplacePart[l, j -> l[[j]]-1]]], {j, 1, Length[l]-1}]][Total[l]];
    f[l_] := Function[n, If[n<2 || l[[-1]]==1, 1, If[l[[1]]==0, 0, If[n==2, Binomial[l[[1]] + l[[2]], l[[1]]]-1, g[l]]]]][Length[l]];
    a[n_] := f[Range[n]];
    Table[a[n], {n, 0, 11}] (* Jean-François Alcover, Feb 27 2017, after Alois P. Heinz *)
Previous Showing 21-25 of 25 results.