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 1-3 of 3 results.

A322298 Number of permutations of [n] in which the length of every increasing run is 0 or 1 (mod 9).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 20, 200, 1520, 9440, 50624, 242816, 1066496, 4361216, 16856556, 64202712, 288983580, 2160645840, 24525417780, 294825080160, 3270522114228, 32898687457422, 302696887652022, 2577419367939422, 20537905525582022, 155236628840778062
Offset: 0

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Author

Alois P. Heinz, Dec 02 2018

Keywords

Crossrefs

A322282 Number of permutations of [n] in which the length of every increasing run is 0 or 1 (mod 8).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 2, 18, 162, 1122, 6402, 31746, 141570, 580866, 2241096, 8693256, 43232904, 362491272, 4067218584, 45304757784, 459941563224, 4236342378840, 35804034476496, 281634733757520, 2106753678778320, 15739783039815120
Offset: 0

Views

Author

Seiichi Manyama, Dec 02 2018

Keywords

Crossrefs

Cf. A000142, A322251 (mod 3), A317111 (mod 4), A322276 (mod 5), A322262 (mod 6), A322297 (mod 7), A322298 (mod 9), A322283 (mod 10).

Programs

  • Mathematica
    m = 28; CoefficientList[1/Normal[Exp[-x]+O[x]^8]+O[x]^m, x]*Range[0, m-1]! (* Jean-François Alcover, Feb 24 2019 *)
  • PARI
    N=40; x='x+O('x^N); Vec(serlaplace(1/sum(k=0, 7, (-x)^k/k!)))

Formula

E.g.f.: 1/(1 - x + x^2/2! - x^3/3! + x^4/4! - x^5/5! + x^6/6! - x^7/7!).

A322283 Number of permutations of [n] in which the length of every increasing run is 0 or 1 (mod 10).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 22, 242, 2002, 13442, 77506, 397826, 1862146, 8085506, 32978946, 127758774, 482490294, 2015041314, 13111486674, 144226353414, 1835958708870, 22030803357420, 240151251989220, 2389590181956120, 21944411982069720, 187919216043135720
Offset: 0

Views

Author

Seiichi Manyama, Dec 02 2018

Keywords

Crossrefs

Cf. A000142, A322251 (mod 3), A317111 (mod 4), A322276 (mod 5), A322262 (mod 6), A322297 (mod 7), A322282 (mod 8), A322298 (mod 9).

Programs

  • Mathematica
    m = 31; CoefficientList[1/Normal[Exp[-x]+O[x]^10]+O[x]^m, x]*Range[0, m-1]! (* Jean-François Alcover, Feb 24 2019 *)
  • PARI
    N=40; x='x+O('x^N); Vec(serlaplace(1/sum(k=0, 9, (-x)^k/k!)))

Formula

E.g.f.: 1/(1 - x + x^2/2! - x^3/3! + x^4/4! - x^5/5! + x^6/6! - x^7/7! + x^8/8! - x^9/9!).
Showing 1-3 of 3 results.