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 11-20 of 22 results. Next

A217057 Number of permutations in S_n containing exactly one increasing subsequence of length 4.

Original entry on oeis.org

0, 0, 0, 0, 1, 12, 102, 770, 5545, 39220, 276144, 1948212, 13817680, 98679990, 710108396, 5150076076, 37641647410, 277202062666, 2056218941678, 15358296210724, 115469557503753, 873561194459596, 6647760790457218, 50871527629923754, 391345137795371013
Offset: 0

Views

Author

Alois P. Heinz, Sep 25 2012

Keywords

Examples

			a(4) = 1: 1234.
a(5) = 12: 12453, 12534, 13425, 13452, 14235, 15234, 23145, 23415, 23451, 31245, 41235, 51234.
		

Crossrefs

Programs

  • Maple
    # programs can be obtained from the Nakamura & Zeilberger link.

A269042 Number of permutations of [2n] avoiding the pattern 12...n.

Original entry on oeis.org

0, 0, 1, 132, 15767, 2190688, 370531683, 77182248916, 19835792076675, 6266271456118776, 2413632612087046844, 1120958514818713738544, 619918692943471064695593, 403190647991638511052901232, 304867528413299672718870216538, 265248225675908889875489731636920
Offset: 0

Views

Author

Alois P. Heinz, Feb 18 2016

Keywords

Examples

			a(2) = 1: 4321.
a(3) = 132: 165432, 216543, 261543, 265143, 265413, 265431, 316542, ..., 653412, 653421, 654132, 654213, 654231, 654312, 654321.
		

Crossrefs

Programs

  • Maple
    h:= proc(l) (n-> add(i, i=l)!/mul(mul(1+l[i]-j+add(`if`(
          l[k]>=j, 1, 0), k=i+1..n), j=1..l[i]), i=1..n))(nops(l))
        end:
    g:= (n, i, l)-> `if`(n=0 or i=1, h([l[], 1$n])^2, `if`(i<1, 0,
                     add(g(n-i*j, i-1, [l[], i$j]), j=0..n/i))):
    a:= n-> `if`(n=0, 0, g(2*n, n-1, [])):
    seq(a(n), n=0..15);
  • Mathematica
    h[l_] := Function[n, Total[l]!/Product[Product[1+l[[i]]-j+Sum[If[l[[k]] >= j, 1, 0], { k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]][Length[l]];
    g[n_, i_, l_] := If[n == 0 || i == 1, h[Join[l, Table[1, {n}]]]^2, If[i < 1, 0, Sum[g[n - i*j, i-1, Join[l, Table[i, {j}]]], {j, 0, n/i}]]];
    a[n_] := If[n == 0, 0, g[2n, n-1, {}]];
    Table[a[n], {n, 0, 15}] (* Jean-François Alcover, Apr 01 2017, translated from Maple *)

Formula

a(n) = (2n)! - A269021(n).
a(n) = A214015(2n,n-1) for n>0.
a(n) ~ (2*n)!. - Vaclav Kotesovec, Mar 26 2016

A072131 T_7(n) in the notation of Bergeron et al., u_k(n) in the notation of Gessel: Related to Young tableaux of bounded height.

Original entry on oeis.org

1, 2, 6, 24, 120, 720, 5040, 40319, 362815, 3626197, 39832877, 476591309, 6162155981, 85494566892, 1264755621000, 19835792076675, 328115505900675, 5698062006852574, 103455252673577866, 1956590161853191160, 38418713005615268760, 780931481835878011620
Offset: 1

Views

Author

Jesse Carlsson (j.carlsson(AT)physics.unimelb.edu.au), Jun 25 2002

Keywords

Crossrefs

Cf. A052399 for T_6(n), A047890 for T_5(n), A047889 for T_4(n).
Column k=7 of A214015.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<8, n!, ((-343035+429858*n
           +238440*n^3+38958*n^4+634756*n^2+2940*n^5+84*n^6)*a(n-1)
           -(1974*n^4+36336*n^3+213240*n^2+407840*n+82425)*(n-1)^2*a(n-2)
           +2*(49875+42646*n+6458*n^2)*(n-1)^2*(n-2)^2*a(n-3)
           -11025*(n-1)^2*(n-2)^2*(n-3)^2*a(n-4))/ ((n+6)^2*(n+10)^2*(n+12)^2))
        end:
    seq (a(n), n=1..30);  # Alois P. Heinz, Sep 26 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1 + l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}] ]; g[n_, i_, l_] := If[n==0 || i==1, h[Join[l, Array[1&, n]]]^2, If[i<1, 0, Sum[g[n - i*j, i-1, Join[l, Array[i&, j]]], {j, 0, n/i}]]]; a[n_] := If[n <= 7, n!, g[n, 7, {}]]; Table[a[n], {n, 1, 30}] (* Jean-François Alcover, Feb 24 2016, after Alois P. Heinz (A214015) *)

Formula

a(n) ~ 6075 * 7^(2*n + 49/2) / (32768 * n^24 * Pi^3). - Vaclav Kotesovec, Sep 10 2014

Extensions

Typo in title corrected by Joel B. Lewis, Jul 16 2009

A072132 T_8(n) in the notation of Bergeron et al., u_k(n) in the notation of Gessel: Related to Young tableaux of bounded height.

Original entry on oeis.org

1, 2, 6, 24, 120, 720, 5040, 40320, 362879, 3628718, 39912738, 478842196, 6221523082, 87002638276, 1302313974900, 20763508263000, 351019617373500, 6266271456118776, 117671982989344680, 2316256222907194304, 47635421509263043024, 1020455890785584587168
Offset: 1

Views

Author

Jesse Carlsson (j.carlsson(AT)physics.unimelb.edu.au), Jun 25 2002

Keywords

Crossrefs

Cf. A052399 for T_6(n), A047890 for T_5(n), A047889 for T_4(n).
Column k=8 of A214015.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<4, n!,
          (-147456*(n+4)*(n-1)^2*(n-2)^2*(n-3)^2*a(n-4)
          +128*(33876+30709*n+6687*n^2+410*n^3)*(n-1)^2*(n-2)^2*a(n-3)
          -4*(1092*n^5+37140*n^4+455667*n^3+2387171*n^2+4649270*n+1206000)*
          (n-1)^2*a(n-2) +(-17075520+(22488312+(29223280+(10509820+(1764252+
          (154164+(6804+120*n)*n)*n)*n)*n)*n)*n)*a(n-1))/
          ((n+16)*(n+7)^2*(n+15)^2*(n+12)^2))
        end:
    seq(a(n), n=1..30);  # Alois P. Heinz, Sep 28 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1 + l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}] ]; g[n_, i_, l_] := If[n==0 || i==1, h[Join[l, Array[1&, n]]]^2, If[i < 1, 0, Sum[g[n - i*j, i-1, Join[l, Array[i&, j]]], {j, 0, n/i}]]]; a[n_] := If[n <= 8, n!, g[n, 8, {}]]; Table[a[n], {n, 1, 30}] (* Jean-François Alcover, Feb 24 2016, after Alois P. Heinz (A214015) *)

Formula

a(n) ~ 1913625 * 2^(6*n + 77) / (n^(63/2) * Pi^(7/2)). - Vaclav Kotesovec, Sep 10 2014

A072133 T_9(n) in the notation of Bergeron et al., u_k(n) in the notation of Gessel: Related to Young tableaux of bounded height.

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628799, 39916699, 478995537, 6226736369, 87166698628, 1307240982000, 20907446718225, 355162464899601, 6384776070987990, 121061600999380138, 2413632612087046844, 50453964720806671644, 1102844526263334763556
Offset: 0

Views

Author

Jesse Carlsson (j.carlsson(AT)physics.unimelb.edu.au), Jun 25 2002

Keywords

Crossrefs

Cf. A052399 for T_6(n), A047890 for T_5(n), A047889 for T_4(n).
Column k=9 of A214015.

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n<5, n!, ((-1110790863+(1520978576+(1772290401+(607308786+
           (101671498+(9464664+(500874+(14124+165*n)*n)*n)*n)*n)*n)*n)*n)*a(n-1)
           -(1129886062*n+559908333*n^2+111239576*n^3+10655238*n^4+8778*n^6
           +491700*n^5 +353895381)*(n-1)^2*a(n-2) +(258011271+234066216*n
           +58221266*n^2+5463876*n^3 +172810*n^4)*(n-1)^2*(n-2)^2*a(n-3)
           -9*(4070430+1504292*n+117469*n^2)* (n-1)^2*(n-2)^2*(n-3)^2*a(n-4)
           +893025*(n-1)^2*(n-2)^2*(n-3)^2*(n-4)^2*a(n-5)) /
           ((n+20)^2*(n+8)^2*(n+18)^2*(n+14)^2))
        end:
    seq(a(n), n=0..30);  # Alois P. Heinz, Oct 10 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1 + l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]]; g[n_, i_, l_] := If[n==0 || i==1, h[Join[l, Array[1 &, n]]]^2, If[i < 1, 0, Sum[g[n - i*j, i - 1, Join[l, Array[i &, j]]], {j, 0, n/i}]]]; a[n_] := If[n <= 9, n!, g[n, 9, {}]]; Table[a[n], {n, 1, 30}] (* Jean-François Alcover, Feb 24 2016, after Alois P. Heinz (A214015) *)

Formula

a(n) ~ 30625 * 3^(4*n + 90) / (2097152 * n^40 * Pi^4). - Vaclav Kotesovec, Sep 10 2014

Extensions

a(0)=1 prepended by Alois P. Heinz, Feb 09 2017

A158432 Number of permutations of 1..n containing the relative rank sequence { 45312 } at any spacing.

Original entry on oeis.org

1, 26, 458, 6996, 101072, 1438112, 20598112, 300892896, 4521034917, 70286670034, 1135485759114, 19121776482564, 336412530327804, 6191800556586104, 119301546930406184, 2406376964044265344, 50786085223779295344, 1120447461653440780128, 25810064637612342838624
Offset: 5

Views

Author

R. H. Hardin, Mar 18 2009

Keywords

Comments

Same series for 54321 12345 45321 21345 12354 54312 34521 32145 12543 54123 23451 43215 15432 51234 21354 34512 32154 21543 45123.

Crossrefs

Programs

  • Maple
    h:= proc(l) local n; n:=nops(l); add(i, i=l)! /mul(mul(1+l[i]-j
          +add(`if`(l[k]>=j, 1, 0), k=i+1..n), j=1..l[i]), i=1..n)
        end:
    g:= (n, i, l)-> `if`(n=0 or i=1, h([l[], 1$n])^2, `if`(i<1, 0,
                     add(g(n-i*j, i-1, [l[], i$j]), j=0..n/i))):
    a:= n-> n! -g(n, 4, []):
    seq(a(n), n=5..25);  # Alois P. Heinz, Jul 05 2012
    # second Maple program
    a:= proc(n) option remember; `if`(n<5, 0, `if`(n=5, 1,
         ((132-142*n-301*n^2-35*n^3+25*n^4+n^5)*a(n-1)
         -2*(10*n^3+33*n^2-181*n-2)*(n-1)^2*a(n-2)
         +64*(n-2)^2*(n-1)^3*a(n-3))/ ((n+4)*(n-5)*(n+3)^2)))
        end:
    seq(a(n), n=5..30);  # Alois P. Heinz, Sep 26 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1+l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]];
    g[n_, i_, l_] := If[n == 0 || i === 1, h[Join[l, Array[1 &, n]]]^2, If[i < 1, 0, Sum[g[n - i*j, i - 1, Join[l, Array[i &, j]]], {j, 0, n/i}]]];
    a[n_] := n! - g[n, 4, {}];
    Table[a[n], {n, 5, 25}] (* Jean-François Alcover, Jun 19 2018, after Alois P. Heinz's first program *)

Formula

a(n) = A214152(n,5) = A000142(n)-A047889(n) = A000142(n)-A214015(n,4).

Extensions

Extended beyond a(16) by Alois P. Heinz, Jul 05 2012

A159139 Number of permutations of 1..n containing the relative rank sequence { 213465 } at any spacing.

Original entry on oeis.org

1, 37, 891, 18043, 337210, 6081686, 108469917, 1941309261, 35187952132, 649951312000, 12286366975723, 238445927000811, 4762398793018878, 98074791689121162, 2085684931155975120, 45859509146309390064, 1043533983233372354613, 24590543663448304800169
Offset: 6

Views

Author

R. H. Hardin, Apr 05 2009

Keywords

Comments

Same series for 654321 123456 564321 213456 123465 654312 456321 321456 123654 654123 345621 432156 126543 651234 564312 456312 321465 213654 564123 345612 432165 216543 561234 234561 543216 165432 612345 456123 321654.

Crossrefs

Programs

  • Maple
    h:= proc(l) local n; n:=nops(l); add(i, i=l)! /mul(mul(1+l[i]-j
          +add(`if`(l[k]>=j, 1, 0), k=i+1..n), j=1..l[i]), i=1..n)
        end:
    g:= proc(n, i, l)
          `if`(n=0 or i=1, h([l[], 1$n])^2, `if`(i<1, 0,
           add(g(n-i*j, i-1, [l[], i$j]), j=0..n/i)))
        end:
    a:= n-> n! -g(n, 5, []):
    seq(a(n), n=6..30);  # Alois P. Heinz, Jul 05 2012
    # second Maple program
    a:= proc(n) option remember; `if`(n<6, 0, `if`(n=6, 1,
         ((2475-4819*n^2-2985*n+175*n^4-1021*n^3+n^6+49*n^5)*a(n-1)
         -(35*n^4+441*n^3-845*n^2-4147*n-489)*(n-1)^2*a(n-2)
         +(-1668+329*n+259*n^2)*(n-1)^2*(n-2)^2*a(n-3)
         -225*(n-1)^2*(n-2)^2*(n-3)^2*a(n-4))/ ((n-6)*(n+6)^2*(n+4)^2)))
        end:
    seq(a(n), n=6..30);  # Alois P. Heinz, Sep 26 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1+l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]];
    g[n_, i_, l_] := If[n == 0 || i === 1, h[Join[l, Array[1 &, n]]]^2, If[i < 1, 0, Sum[g[n - i*j, i - 1, Join[l, Array[i &, j]]], {j, 0, n/i}]]];
    a[n_] := n! - g[n, 5, {}];
    Table[a[n], {n, 6, 30}] (* Jean-François Alcover, Jun 19 2018, from first Maple program *)

Formula

a(n) = A214152(n,6) = A000142(n)-A047890(n) = A000142(n)-A214015(n,5). - Alois P. Heinz, Jul 05 2012

Extensions

More terms from Alois P. Heinz, Jul 05 2012

A159175 Number of permutations of 1..n containing the relative rank sequence { 1234567 } at any spacing.

Original entry on oeis.org

1, 50, 1578, 40884, 958809, 21353634, 463945294, 9996042284, 215831724525, 4702905606350, 103912444955422, 2336099774748540, 53567906041439136, 1255172323669315848, 30095426182382305848, 739238316780966277616, 18619024923770934306358, 481234428294016650524172
Offset: 7

Views

Author

R. H. Hardin Apr 05 2009

Keywords

Comments

Same series (among rank sequences with inversion = reversal) for 3214765 2134576.

Crossrefs

Programs

  • Maple
    h:= proc(l) local n; n:=nops(l); add(i, i=l)! /mul(mul(1+l[i]-j
          +add(`if`(l[k]>=j, 1, 0), k=i+1..n), j=1..l[i]), i=1..n)
        end:
    g:= (n, i, l)-> `if`(n=0 or i=1, h([l[], 1$n])^2, `if`(i<1, 0,
                     add(g(n-i*j, i-1, [l[], i$j]), j=0..n/i))):
    a:= n-> n! -g(n, 6, []):
    seq(a(n), n=7..25);  # Alois P. Heinz, Jul 05 2012
    # second Maple program
    a:= proc(n) option remember; `if`(n<7, 0, `if`(n=7, 1, ((-93464*n+1072*n^4
          +72128-125284*n^2+84*n^6+994*n^5-30491*n^3+n^7) *a(n-1)
          -4*(14*n^5+399*n^4+1124*n^3-7354*n^2-23983*n-5042)*(n-1)^2 *a(n-2)
          +4*(-7359-2629*n+1596*n^2+196*n^3)*(n-1)^2*(n-2)^2 *a(n-3)
          -1152*(1+2*n)*(n-1)^2*(n-2)^2*(n-3)^2 *a(n-4))/
           ((n-7)*(n+9)*(n+8)^2*(n+5)^2)))
        end:
    seq(a(n), n=7..30);  # Alois P. Heinz, Sep 27 2012
  • Mathematica
    h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]!/Product[Product[1+l[[i]] - j + Sum[If[l[[k]] >= j, 1, 0], {k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]];
    g[n_, i_, l_] := If[n == 0 || i === 1, h[Join[l, Array[1 &, n]]]^2, If[i < 1, 0, Sum[g[n - i*j, i - 1, Join[l, Array[i &, j]]], {j, 0, n/i}]]];
    a[n_] := n! - g[n, 6, {}];
    Table[a[n], {n, 7, 25}] (* Jean-François Alcover, Jun 19 2018, from first Maple program *)

Formula

a(n) = A214152(n,7) = A000142(n)-A052399(n) = A000142(n)-A214015(n,6). - Alois P. Heinz, Jul 05 2012

Extensions

Extended beyond a(16) by Alois P. Heinz, Jul 05 2012

A217675 Number of permutations in S_n containing an increasing subsequence of length 8.

Original entry on oeis.org

1, 65, 2603, 83923, 2410291, 64864819, 1683724308, 42918747000, 1086997811325, 27571922195325, 704311698875426, 18189847735254134, 476311846323448840, 12672229166094171240, 343069245941729668380, 9461927811882316662636, 266091066751920438364275
Offset: 8

Views

Author

Alois P. Heinz, Oct 10 2012

Keywords

Examples

			a(8) = 1: 12345678.
		

Crossrefs

Programs

  • Maple
    b:= proc(n) option remember; `if`(n<8, n!, ((-343035+429858*n
           +238440*n^3+38958*n^4+634756*n^2+2940*n^5+84*n^6)*b(n-1)
           -(1974*n^4+36336*n^3+213240*n^2+407840*n+82425)*(n-1)^2*b(n-2)
           +2*(49875+42646*n+6458*n^2)*(n-1)^2*(n-2)^2*b(n-3)
           -11025*(n-1)^2*(n-2)^2*(n-3)^2*b(n-4))/ ((n+6)^2*(n+10)^2*(n+12)^2))
        end:
    a:= n-> n! -b(n):
    seq(a(n), n=8..25);

Formula

a(n) = A214152(n,8) = A000142(n)-A072131(n) = A000142(n)-A214015(n,7).

A217676 Number of permutations in S_n containing an increasing subsequence of length 9.

Original entry on oeis.org

1, 82, 4062, 159404, 5497718, 175652924, 5360393100, 159281625000, 4667810722500, 136102249609224, 3973117419487320, 116645785269445696, 3455520662446396976, 103544836992023092832, 3144187412886704149472, 96883566754646092037696, 3032518386648514382974097
Offset: 9

Views

Author

Alois P. Heinz, Oct 10 2012

Keywords

Examples

			a(9) = 1: 123456789.
		

Crossrefs

Programs

  • Maple
    b:= proc(n) option remember; `if`(n<4, n!,
          (-147456*(n+4)*(n-1)^2*(n-2)^2*(n-3)^2*b(n-4)
          +128*(33876+30709*n+6687*n^2+410*n^3)*(n-1)^2*(n-2)^2*b(n-3)
          -4*(1092*n^5+37140*n^4+455667*n^3+2387171*n^2+4649270*n+1206000)*
          (n-1)^2*b(n-2) +(-17075520+(22488312+(29223280+(10509820+(1764252+
          (154164+(6804+120*n)*n)*n)*n)*n)*n)*n)*b(n-1))/
          ((n+16)*(n+7)^2*(n+15)^2*(n+12)^2))
        end:
    a:= n-> n! -b(n):
    seq(a(n), n=9..30);

Formula

a(n) = A214152(n,9) = A000142(n)-A072132(n) = A000142(n)-A214015(n,8).
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