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.

A152511 1/60 of the number of permutations of 5 indistinguishable copies of 1..n with exactly 4 local maxima.

Original entry on oeis.org

0, 1, 4194, 5825786, 5682784528, 4873147413516, 3978083870212150, 3186605615943562016, 2534375865966184697328, 2010275266425805924583168, 1593002777198909770195152928, 1261900375041824878511515546368, 999492236937050258502770760302080, 791616311022376735886612880860890112
Offset: 1

Views

Author

R. H. Hardin, Dec 06 2008

Keywords

Crossrefs

Programs

  • PARI
    \\ PeaksBySig defined in A334774.
    a(n) = {PeaksBySig(vector(n,i,5), [3])[1]/60} \\ Andrew Howroyd, May 12 2020

Extensions

Terms a(7) and beyond from Andrew Howroyd, May 12 2020

A152512 1/6 of the number of permutations of 5 indistinguishable copies of 1..n with exactly 5 local maxima.

Original entry on oeis.org

0, 1, 51408, 331072352, 1080698915350, 2691500727775616, 5953257961411738328, 12474940206857421730672, 25498614004537897031551640, 51527434528518884637847012176, 103587934174554666918594336695328, 207763415020909344351469183584249792
Offset: 1

Views

Author

R. H. Hardin, Dec 06 2008

Keywords

Crossrefs

Programs

  • PARI
    \\ PeaksBySig defined in A334774.
    a(n) = {PeaksBySig(vector(n,i,5), [4])[1]/6} \\ Andrew Howroyd, May 12 2020

Extensions

Terms a(7) and beyond from Andrew Howroyd, May 12 2020

A152514 1/7 of the number of permutations of 6 indistinguishable copies of 1..n with exactly 3 local maxima.

Original entry on oeis.org

0, 50, 42035, 22286180, 10637332433, 4951385566862, 2291336707020095, 1058974724436063848, 489282897651319234589, 226052182024142033107730, 104436435218150212780973867, 48249663449218668484434011660, 22291347308935948403947280066153, 10298602712004866151067473095589974
Offset: 1

Views

Author

R. H. Hardin, Dec 06 2008

Keywords

Crossrefs

Programs

  • PARI
    \\ PeaksBySig defined in A334774.
    a(n) = {PeaksBySig(vector(n,i,6), [2])[1]/7} \\ Andrew Howroyd, May 12 2020
    
  • PARI
    concat(0, Vec(x^2*(50 + 9485*x - 176155*x^2 - 6027882*x^3 - 3111696*x^4) / ((1 - 7*x)^3*(1 - 84*x)^2*(1 - 462*x)) + O(x^15))) \\ Colin Barker, Jul 19 2020

Formula

From Colin Barker, Jul 19 2020: (Start)
G.f.: x^2*(50 + 9485*x - 176155*x^2 - 6027882*x^3 - 3111696*x^4) / ((1 - 7*x)^3*(1 - 84*x)^2*(1 - 462*x)).
a(n) = 651*a(n-1) - 98049*a(n-2) + 5130937*a(n-3) - 81120186*a(n-4) + 0*a(n-5) - 0*a(n-6) for n>6.
(End)

Extensions

Terms a(7) and beyond from Andrew Howroyd, May 12 2020

A152515 1/7 of the number of permutations of 6 indistinguishable copies of 1..n with exactly 4 local maxima.

Original entry on oeis.org

0, 50, 321315, 824734660, 1615456263653, 2896390530019554, 5041787615373941503, 8691245890710074064416, 14935422227548071392068185, 25640373750597951750787951486, 44004685572828990924291145512563, 75515015253707870321041620455156412, 129585276023496655588712207028376849165
Offset: 1

Views

Author

R. H. Hardin, Dec 06 2008

Keywords

Crossrefs

Programs

  • PARI
    \\ PeaksBySig defined in A334774.
    a(n) = {PeaksBySig(vector(n,i,6), [3])[1]/7} \\ Andrew Howroyd, May 12 2020

Extensions

Terms a(7) and beyond from Andrew Howroyd, May 12 2020

A152516 1/21 of the number of permutations of 6 indistinguishable copies of 1..n with exactly 5 local maxima.

Original entry on oeis.org

0, 5, 285365, 3328373375, 23122804891093, 132106319858700205, 697701196338306192217, 3568377130807709398000279, 18013809185839252548978200161, 90462608845509339028810174966669, 453352973288072573009512458761236141, 2270154484704085339079608424120307696559
Offset: 1

Views

Author

R. H. Hardin, Dec 06 2008

Keywords

Crossrefs

Programs

  • PARI
    \\ PeaksBySig defined in A334774.
    a(n) = {PeaksBySig(vector(n,i,6), [4])[1]/21} \\ Andrew Howroyd, May 12 2020

Extensions

Terms a(7) and beyond from Andrew Howroyd, May 12 2020
Previous Showing 21-25 of 25 results.