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 11-16 of 16 results.

A256202 Number of permutations in S_n that avoid the pattern 53241.

Original entry on oeis.org

1, 1, 2, 6, 24, 119, 694, 4580, 33256, 260370, 2166120, 18945144, 172810050, 1633997788, 15939893003, 159820729208, 1641980432159, 17242378256155, 184674461615836, 2013829450204384, 22324460502429244, 251250502143635615, 2867467023751687892, 33152272498223444540
Offset: 0

Views

Author

N. J. A. Sloane, Mar 19 2015

Keywords

Crossrefs

Representatives for the 16 Wilf-equivalence patterns of length 5 are given in A116485, A047889, and A256195-A256208.
Cf. A099952.

Programs

  • Mathematica
    avoid[n_, pat_] := Module[{p1 = pat[[1]], p2 = pat[[2]], p3 = pat[[3]], p4 = pat[[4]], p5 = pat[[5]], lseq = {}, i, p,
        lpat = Subsets[(n + 1) - Range[n], {Length[pat]}],
        psn = Permutations[Range[n]]},
       For[i = 1, i <= Length[lpat], i++,
        p = lpat[[i]];
        AppendTo[lseq, Select[psn, MemberQ[#, {_, p[[p1]], _, p[[p2]], _, p[[p3]], _, p[[p4]], _, p[[p5]], _}, {0}] &]];
        ]; n! - Length[Union[Flatten[lseq, 1]]]];
    Table[avoid[n, {5, 3, 2, 4, 1}], {n, 0, 8}]  (* Robert Price, Mar 27 2020 *)

Extensions

More terms from Anthony Guttmann, Sep 29 2021

A256203 Number of permutations in S_n that avoid the pattern 43251.

Original entry on oeis.org

1, 1, 2, 6, 24, 119, 694, 4581, 33283, 260805, 2171393, 18994464, 173094540, 1632480259, 15851668551, 157824649955, 1605839173312, 16652321922596, 175596537163347, 1879357191026029, 20382942631855557, 223719376672365073, 2482094083780961295, 27808544385768051233
Offset: 0

Views

Author

N. J. A. Sloane, Mar 19 2015

Keywords

Crossrefs

Representatives for the 16 Wilf-equivalence patterns of length 5 are given in A116485, A047889, and A256195-A256208.
Cf. A099952.

Programs

  • Mathematica
    avoid[n_, pat_] := Module[{p1 = pat[[1]], p2 = pat[[2]], p3 = pat[[3]], p4 = pat[[4]], p5 = pat[[5]], lseq = {}, i, p,
        lpat = Subsets[(n + 1) - Range[n], {Length[pat]}],
        psn = Permutations[Range[n]]},
       For[i = 1, i <= Length[lpat], i++,
        p = lpat[[i]];
        AppendTo[lseq, Select[psn, MemberQ[#, {_, p[[p1]], _, p[[p2]], _, p[[p3]], _, p[[p4]], _, p[[p5]], _}, {0}] &]];
        ]; n! - Length[Union[Flatten[lseq, 1]]]];
    Table[avoid[n, {4, 3, 2, 5, 1}], {n, 0, 8}]  (* Robert Price, Mar 27 2020 *)

Extensions

More terms from Anthony Guttmann, Sep 29 2021

A256204 Number of permutations in S_n that avoid the pattern 32541.

Original entry on oeis.org

1, 1, 2, 6, 24, 119, 694, 4581, 33284, 260847, 2172454, 19015582, 173461305, 1638327423, 15939733122, 159099927785, 1623799173782, 16900201391546, 178967276844263, 1924689980696921, 20987593594256974, 231734179050033660, 2587835777992844938, 29198736751160012102
Offset: 0

Views

Author

N. J. A. Sloane, Mar 19 2015

Keywords

Crossrefs

Representatives for the 16 Wilf-equivalence patterns of length 5 are given in A116485, A047889, and A256195-A256208.
Cf. A099952.

Programs

  • Mathematica
    avoid[n_, pat_] := Module[{p1 = pat[[1]], p2 = pat[[2]], p3 = pat[[3]], p4 = pat[[4]], p5 = pat[[5]], lseq = {}, i, p,
        lpat = Subsets[(n + 1) - Range[n], {Length[pat]}],
        psn = Permutations[Range[n]]},
       For[i = 1, i <= Length[lpat], i++,
        p = lpat[[i]];
        AppendTo[lseq, Select[psn, MemberQ[#, {_, p[[p1]], _, p[[p2]], _, p[[p3]], _, p[[p4]], _, p[[p5]], _}, {0}] &]];
        ]; n! - Length[Union[Flatten[lseq, 1]]]];
    Table[avoid[n, {3, 2, 5, 4, 1}], {n, 0, 8}]  (* Robert Price, Mar 27 2020 *)

Extensions

More terms from Anthony Guttmann, Sep 29 2021

A256205 Number of permutations in S_n that avoid the pattern 34215.

Original entry on oeis.org

1, 1, 2, 6, 24, 119, 694, 4581, 33285, 260886, 2173374, 19032746, 173741467, 1642533692, 15999488304, 159917206735, 1634681988983, 17042352950764, 180798150762914, 1948027746498015, 21282786390947602, 235446451502773103, 2634317655935012208, 29778833170013213300
Offset: 0

Views

Author

N. J. A. Sloane, Mar 19 2015

Keywords

Crossrefs

Representatives for the 16 Wilf-equivalence patterns of length 5 are given in A116485, A047889, and A256195-A256208.
Cf. A099952.

Programs

  • Mathematica
    avoid[n_, pat_] := Module[{p1 = pat[[1]], p2 = pat[[2]], p3 = pat[[3]], p4 = pat[[4]], p5 = pat[[5]], lseq = {}, i, p,
        lpat = Subsets[(n + 1) - Range[n], {Length[pat]}],
        psn = Permutations[Range[n]]},
       For[i = 1, i <= Length[lpat], i++,
        p = lpat[[i]];
        AppendTo[lseq, Select[psn, MemberQ[#, {_, p[[p1]], _, p[[p2]], _, p[[p3]], _, p[[p4]], _, p[[p5]], _}, {0}] &]];
        ]; n! - Length[Union[Flatten[lseq, 1]]]];
    Table[avoid[n, {3, 4, 2, 1, 5}], {n, 0, 8}]  (* Robert Price, Mar 27 2020 *)

Extensions

More terms from Anthony Guttmann, Sep 29 2021

A256206 Number of permutations in S_n that avoid the pattern 42315.

Original entry on oeis.org

1, 1, 2, 6, 24, 119, 694, 4581, 33287, 260967, 2175379, 19072271, 174426353, 1653484169, 16165513608, 162344264849, 1669261805697, 17526017429722, 187472773174466, 2039233971499931, 22520066337196663, 252141732452056894, 2858721279079666465, 32786666580814894741
Offset: 0

Views

Author

N. J. A. Sloane, Mar 19 2015

Keywords

Crossrefs

Representatives for the 16 Wilf-equivalence patterns of length 5 are given in A116485, A047889, and A256195-A256208.
Cf. A099952.

Programs

  • Mathematica
    avoid[n_, pat_] := Module[{p1 = pat[[1]], p2 = pat[[2]], p3 = pat[[3]], p4 = pat[[4]], p5 = pat[[5]], lseq = {}, i, p,
        lpat = Subsets[(n + 1) - Range[n], {Length[pat]}],
        psn = Permutations[Range[n]]},
       For[i = 1, i <= Length[lpat], i++,
        p = lpat[[i]];
        AppendTo[lseq, Select[psn, MemberQ[#, {_, p[[p1]], _, p[[p2]], _, p[[p3]], _, p[[p4]], _, p[[p5]], _}, {0}] &]];
        ]; n! - Length[Union[Flatten[lseq, 1]]]];
    Table[avoid[n, {4, 2, 3, 1, 5}], {n, 0, 8}]  (* Robert Price, Mar 27 2020 *)

Extensions

More terms from Anthony Guttmann, Sep 29 2021

A256207 Number of permutations in S_n that avoid the pattern 53421.

Original entry on oeis.org

1, 1, 2, 6, 24, 119, 694, 4582, 33325, 261853, 2191902, 19344408, 178582940, 1713999264, 17019444969, 174149184184, 1830279810276, 19703572779755, 216769635980879, 2432308876304981, 27788506478197951, 322770995262901091, 3806657237502632706, 45532086120583546634
Offset: 0

Views

Author

N. J. A. Sloane, Mar 19 2015

Keywords

Crossrefs

Representatives for the 16 Wilf-equivalence patterns of length 5 are given in A116485, A047889, and A256195-A256208.
Cf. A099952.

Programs

  • Mathematica
    avoid[n_, pat_] := Module[{p1 = pat[[1]], p2 = pat[[2]], p3 = pat[[3]], p4 = pat[[4]], p5 = pat[[5]], lseq = {}, i, p,
        lpat = Subsets[(n + 1) - Range[n], {Length[pat]}],
        psn = Permutations[Range[n]]},
       For[i = 1, i <= Length[lpat], i++,
        p = lpat[[i]];
        AppendTo[lseq, Select[psn, MemberQ[#, {_, p[[p1]], _, p[[p2]], _, p[[p3]], _, p[[p4]], _, p[[p5]], _}, {0}] &]];
        ]; n! - Length[Union[Flatten[lseq, 1]]]];
    Table[avoid[n, {5, 3, 4, 2, 1}], {n, 0, 8}]  (* Robert Price, Mar 27 2020 *)

Extensions

More terms from Anthony Guttmann, Sep 29 2021
Previous Showing 11-16 of 16 results.