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.

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A176487 Triangle read by rows: T(n,k) = binomial(n,k) + A008292(n+1,k+1) - 1.

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 13, 13, 1, 1, 29, 71, 29, 1, 1, 61, 311, 311, 61, 1, 1, 125, 1205, 2435, 1205, 125, 1, 1, 253, 4313, 15653, 15653, 4313, 253, 1, 1, 509, 14635, 88289, 156259, 88289, 14635, 509, 1, 1, 1021, 47875, 455275, 1310479, 1310479, 455275, 47875, 1021, 1
Offset: 0

Views

Author

Roger L. Bagula, Apr 19 2010

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    5,     1;
  1,   13,    13,      1;
  1,   29,    71,     29,       1;
  1,   61,   311,    311,      61,       1;
  1,  125,  1205,   2435,    1205,     125,      1;
  1,  253,  4313,  15653,   15653,    4313,    253,     1;
  1,  509, 14635,  88289,  156259,   88289,  14635,   509,    1;
  1, 1021, 47875, 455275, 1310479, 1310479, 455275, 47875, 1021,   1;
		

Crossrefs

Programs

  • Magma
    A176487:= func< n, k | Binomial(n, k) + EulerianNumber(n+1, k) - 1 >;
    [A176487(n, k): k in [0..n], n in [0..12]]; // G. C. Greubel, Dec 31 2024
    
  • Maple
    A176487 := proc(n,k)
        binomial(n,k)+A008292(n+1,k+1)-1 ;
    end proc: # R. J. Mathar, Jun 16 2015
  • Mathematica
    Needs["Combinatorica`"];
    T[n_, k_, 0]:= Binomial[n, k];
    T[n_, k_, 1]:= Eulerian[1 + n, k];
    T[n_, k_, q_]:= T[n,k,q] = T[n,k,q-1] + T[n,k,q-2] - 1;
    Table[T[n,k,2], {n,0,12}, {k,0,n}]//Flatten
  • SageMath
    # from sage.all import * # (use for Python)
    from sage.combinat.combinat import eulerian_number
    def A176487(n,k): return binomial(n,k) +eulerian_number(n+1,k) -1
    print(flatten([[A176487(n,k) for k in range(n+1)] for n in range(13)])) # G. C. Greubel, Dec 31 2024

Formula

T(n, k) = A007318(n,k) + A008292(n+1,k+1) - 1, 0 <= k <= n.
Sum_{k=0..n} T(n, k) = 2^n - n + A033312(n+1) (row sums).
T(n, k) = 2*A141689(n+1,k+1) - 1. - R. J. Mathar, Jan 19 2011
From G. C. Greubel, Dec 31 2024: (Start)
T(n, n-k) = T(n, k).
T(n, 1) = A036563(n+1).
Sum_{k=0..n} (-1)^k * T(n,k) = ((-1)^(n/2)*A000182(n/2 + 1) - 1)*(1 + (-1)^n)/2 + [n=0]. (End)

A001244 Eulerian numbers (Euler's triangle: column k=8 of A008292, column k=7 of A173018).

Original entry on oeis.org

1, 502, 47840, 2203488, 66318474, 1505621508, 27971176092, 447538817472, 6382798925475, 83137223185370, 1006709967915228, 11485644635009424, 124748182104463860, 1300365805079109480, 13093713503185076040
Offset: 8

Views

Author

Keywords

Comments

There are 2 versions of Euler's triangle:
* A008292 Classic version of Euler's triangle used by Comtet (1974).
* A173018 Version of Euler's triangle used by Graham, Knuth and Patashnik in Concrete Math. (1990).
Euler's triangle rows and columns indexing conventions:
* A008292 The rows and columns of the Eulerian triangle are both indexed starting from 1. (Classic version: used in the classic books by Riordan and Comtet.)
* A173018 The rows and columns of the Eulerian triangle are both indexed starting from 0. (Graham et al.)
For the general computation of the o.g.f. and e.g.f. see A123125. - Wolfdieter Lang, Apr 03 2017

References

  • L. Comtet, "Permutations by Number of Rises; Eulerian Numbers." §6.5 in Advanced Combinatorics: The Art of Finite and Infinite Expansions, rev. enl. ed. Dordrecht, Netherlands: Reidel, pp. 51 and 240-246, 1974.
  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 243.
  • F. N. David and D. E. Barton, Combinatorial Chance. Hafner, NY, 1962, p. 151.
  • F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 2601.
  • J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 215.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A008292 (classic version of Euler's triangle used by Comtet (1974).)
Cf. A173018 (version of Euler's triangle used by Graham, Knuth and Patashnik in Concrete Math. (1990).)
Cf. A123125 (row reversed version of A173018).
Cf. A000012, A000460, A000498, A000505, A000514, A001243 (columns for smaller k).

Programs

  • Magma
    A001244:= func< n | EulerianNumber(n,7) >;
    [A001244(n): n in [8..40]]; // G. C. Greubel, Dec 31 2024
    
  • Mathematica
    k = 8; Table[k^(n + k - 1) + Sum[(-1)^i/i!*(k - i)^(n + k - 1) * Product[n + k + 1 - j, {j, 1, i}], {i, 1, k - 1}], {n, 1, 15}] (* Michael De Vlieger, Aug 04 2015, after PARI *)
  • PARI
    A001244(n)=8^(n+8-1)+sum(i=1,8-1,(-1)^i/i!*(8-i)^(n+8-1)*prod(j=1,i,n+8+1-j))
    
  • Python
    from sage.combinat.combinat import eulerian_number
    print([eulerian_number(n,7) for n in range(8,41)]) # G. C. Greubel, Dec 31 2024

Formula

a(n) = 8^(n+8-1) + Sum_{i=1..8-1} ((-1)^i/i!)*(8-i)^(n+8-1) * Product_{j=1..i} (n+8+1 - j). - Randall L Rathbun, Jan 23 2002
a(n) = k^n + Sum_{j=1..k-1} (-1)^j*binomial(n+1,j)*(k-j)^n, with k = 8, for n >= 8. - G. C. Greubel, Dec 31 2024

Extensions

More terms from Christian G. Bower, May 12 2000

A154694 Triangle read by rows: T(n,k) = ((3/2)^k*2^n + (2/3)^k*3^n)*A008292(n+1,k+1).

Original entry on oeis.org

2, 5, 5, 13, 48, 13, 35, 330, 330, 35, 97, 2028, 4752, 2028, 97, 275, 11970, 54360, 54360, 11970, 275, 793, 69840, 557388, 1043712, 557388, 69840, 793, 2315, 407550, 5409180, 16868520, 16868520, 5409180, 407550, 2315, 6817, 2388516, 51011136, 247761072, 404844480, 247761072, 51011136, 2388516, 6817
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Jan 14 2009

Keywords

Examples

			Triangle begins as:
     2;
     5,      5;
    13,     48,      13;
    35,    330,     330,       35;
    97,   2028,    4752,     2028,       97;
   275,  11970,   54360,    54360,    11970,     275;
   793,  69840,  557388,  1043712,   557388,   69840,    793;
  2315, 407550, 5409180, 16868520, 16868520, 5409180, 407550, 2315;
		

Crossrefs

Cf. A004123 (row sums), A154693, A256890.

Programs

  • Magma
    A154694:= func< n,k | (2^(n-k)*3^k+2^k*3^(n-k))*EulerianNumber(n+1, k) >;
    [A154694(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jan 18 2025
    
  • Maple
    A154694 := proc(n,m)
        (3^m*2^(n-m)+2^m*3^(n-m))*A008292(n+1,m+1) ;
    end proc:
    seq(seq( A154694(n,m),m=0..n),n=0..10) ; # R. J. Mathar, Mar 11 2024
  • Mathematica
    T[n_, k_, p_, q_] := (p^(n - k)*q^k + p^k*q^(n - k))*Eulerian[n+1,k];
    Table[T[n,k,2,3], {n,0,12}, {k,0,n}]//Flatten
  • Python
    from sage.all import *
    from sage.combinat.combinat import eulerian_number
    def A154694(n,k): return (pow(2,n-k)*pow(3,k)+pow(2,k)*pow(3,n-k))*eulerian_number(n+1,k)
    print(flatten([[A154694(n,k) for k in range(n+1)] for n in range(13)])) # G. C. Greubel, Jan 18 2025

Formula

Sum_{k=0..n} T(n, k) = A004123(n+2).

Extensions

Definition simplified by the Assoc. Eds. of the OEIS, Jun 07 2010

A055325 Matrix inverse of Euler's triangle A008292.

Original entry on oeis.org

1, -1, 1, 3, -4, 1, -23, 33, -11, 1, 425, -620, 220, -26, 1, -18129, 26525, -9520, 1180, -57, 1, 1721419, -2519664, 905765, -113050, 5649, -120, 1, -353654167, 517670461, -186123259, 23248085, -1166221, 25347, -247, 1, 153923102577
Offset: 1

Views

Author

Christian G. Bower, May 12 2000

Keywords

Examples

			Triangle starts:
  [1]         1;
  [2]        -1,         1;
  [3]         3,        -4,          1;
  [4]       -23,        33,        -11,        1;
  [5]       425,      -620,        220,      -26,        1;
  [6]    -18129,     26525,      -9520,     1180,      -57,     1;
  [7]   1721419,  -2519664,     905765,  -113050,     5649,  -120,    1;
  [8]-353654167, 517670461, -186123259, 23248085, -1166221, 25347, -247, 1;
		

Crossrefs

Programs

  • Maple
    A008292:= proc(n, k) option remember;
      if k < 1 or k > n then 0
      elif k = 1 or k = n then 1
      else (k*procname(n-1, k)+(n-k+1)*procname(n-1, k-1))
      fi
    end proc:
    T:= Matrix(10,10,(i,j) -> A008292(i,j)):
    R:= T^(-1):
    seq(seq(R[i,j],j=1..i),i=1..10); # Robert Israel, May 25 2018
  • Mathematica
    m = 10 (*rows*);
    t[n_, k_] := Sum[(-1)^j*(k-j)^n*Binomial[n+1, j], {j, 0, k}];
    M = Array[t, {m, m}] // Inverse;
    Table[M[[i, j]], {i, 1, m}, {j, 1, i}] // Flatten (* Jean-François Alcover, Mar 05 2019 *)
    T[1, 1] := 1; T[n_, k_]/;1<=k<=n := T[n, k] = (n-k+1) T[n-1, k-1] + k T[n-1, k]; T[n_, k_] := 0;(*A008292*)
    iT[n_, n_]/;n>=1 := 1; iT[n_, k_]/;1<=kA055325*)
    Flatten@Table[iT[n, k], {n, 1, 9}, {k, 1, n}] (* Oliver Seipel, Feb 10 2025 *)

A141686 Triangle read by rows: T(n, k) = binomial(n-1, k-1)*A008292(n, k).

Original entry on oeis.org

1, 1, 1, 1, 8, 1, 1, 33, 33, 1, 1, 104, 396, 104, 1, 1, 285, 3020, 3020, 285, 1, 1, 720, 17865, 48320, 17865, 720, 1, 1, 1729, 90153, 546665, 546665, 90153, 1729, 1, 1, 4016, 409024, 4941104, 10933300, 4941104, 409024, 4016, 1, 1, 9117, 1722240, 38236128, 165104604, 165104604, 38236128, 1722240, 9117, 1
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 08 2008

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    8,       1;
  1,   33,      33,        1;
  1,  104,     396,      104,         1;
  1,  285,    3020,     3020,       285,         1;
  1,  720,   17865,    48320,     17865,       720,        1;
  1, 1729,   90153,   546665,    546665,     90153,     1729,       1;
  1, 4016,  409024,  4941104,  10933300,   4941104,   409024,    4016,    1;
  1, 9117, 1722240, 38236128, 165104604, 165104604, 38236128, 1722240, 9117, 1;
		

Crossrefs

Programs

  • Haskell
    a141686 n k = a141686_tabl !! (n-1) !! (k-1)
    a141686_row n = a141686_tabl !! (n-1)
    a141686_tabl = zipWith (zipWith (*)) a007318_tabl a008292_tabl
    -- Reinhard Zumkeller, Apr 16 2014
    
  • Magma
    A141686:= func< n, k | Binomial(n-1, k-1)*EulerianNumber(n, k-1) >;
    [A141686(n, k): k in [1..n], n in [1..12]]; // G. C. Greubel, Dec 31 2024
    
  • Mathematica
    (* Recurrence for A008292 *)
    f[n_, k_]:= If[k==1||k==n,1, (n-k+1)*f[n-1,k-1] + k*f[n-1,k]];
    Table[f[n, k]*Binomial[n-1,k-1], {n,12}, {k,n}]//Flatten
    (* Second program *)
    Needs["Combinatorica`"];
    A141686[n_, k_]:= Binomial[n-1,k-1]*Eulerian[n,k-1];
    Table[A141686[n,k], {n,12}, {k,n}]//Flatten (* G. C. Greubel, Dec 31 2024 *)
  • Python
    # or SageMath
    from sage.combinat.combinat import eulerian_number
    def A141686(n,k): return binomial(n-1,k-1)*eulerian_number(n,k-1)
    print(flatten([[A141686(n,k) for k in range(1,n+1)] for n in range(1,13)])) # G. C. Greubel, Dec 31 2024

Formula

T(n, k) = T(n, n-k+1).
Sum_{k=1..n} T(n, k) = A104098(n) (row sums).

Extensions

keyword:tabl inserted, indices corrected by the Assoc. Eds. of the OEIS, Jun 30 2010

A168562 Sum of squares of Eulerian numbers in row n of triangle A008292 with a(0)=1.

Original entry on oeis.org

1, 1, 2, 18, 244, 5710, 188908, 8702820, 524888040, 40393084950, 3853034107900, 446671026849916, 61824801560228056, 10072685383683311116, 1907978676359896992824, 415795605119514578204616, 103294156408291202467520976, 29018125910193347265466916070
Offset: 0

Views

Author

Paul D. Hanna, Nov 29 2009

Keywords

Comments

Row sums of Eulerian triangle A008292 yield the factorials.

Examples

			a(1) = 1 = 1;
a(2) = 1 + 1 = 2;
a(3) = 1 + 4^2 + 1 = 18;
a(4) = 1 + 11^2 + 11^2 + 1 = 244;
a(5) = 1 + 26^2 + 66^2 + 26^2 + 1 = 5710;
a(6) = 1 + 57^2 + 302^2 + 302^2 + 57^2 + 1 = 188908.
		

Crossrefs

Cf. A008292.
Column k=2 of A335545.

Programs

  • Maple
    a:= n-> add(combinat[eulerian1](n, k)^2, k=0..n):
    seq(a(n), n=0..18);  # Alois P. Heinz, Sep 10 2020
  • PARI
    {a(n)=sum(k=0,n,sum(j=0, k, (-1)^j*(k-j)^n*binomial(n+1, j))^2)}

Formula

a(n) = Sum_{k=0..n} [ Sum_{j=0..k} (-1)^j*(k-j)^n*C(n+1, j) ]^2.

A176490 Triangle T(n,k) = A008292(n+1,k+1) + A060187(n+1,k+1)- 1 read along rows 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 1, 9, 1, 1, 33, 33, 1, 1, 101, 295, 101, 1, 1, 293, 1983, 1983, 293, 1, 1, 841, 11733, 25963, 11733, 841, 1, 1, 2425, 64949, 275341, 275341, 64949, 2425, 1, 1, 7053, 346219, 2573521, 4831203, 2573521, 346219, 7053, 1, 1, 20685, 1804179, 22163163
Offset: 0

Views

Author

Roger L. Bagula, Apr 19 2010

Keywords

Comments

Row sums are: 1, 2, 11, 68, 499, 4554, 51113, 685432, 10684791, 189423350, 3755807989,....
Conjecture on the row sums s(n): 859*(n+1)*s(n) +(-2577*n^2-15955*n+33324)*s(n-1) +(1718*n^3+39275*n^2-102106*n-16383)*s(n-2) +(-25038*n^3+35127*n^2+252701*n-453082)*s(n-3) +(n-3)*(57834*n^2-211893*n+212386)*s(n-4) -2*(17257*n-29530)*(n-3)*(n-4)*a(n-5)=0. - R. J. Mathar, Jun 16 2015

Examples

			1;
1, 1;
1, 9, 1;
1, 33, 33, 1;
1, 101, 295, 101, 1;
1, 293, 1983, 1983, 293, 1;
1, 841, 11733, 25963, 11733, 841, 1;
1, 2425, 64949, 275341, 275341, 64949, 2425, 1;
1, 7053, 346219, 2573521, 4831203, 2573521, 346219, 7053, 1;
1, 20685, 1804179, 22163163, 70723647, 70723647, 22163163, 1804179, 20685, 1;
1, 61073, 9268777, 180504391, 916661395, 1542816715, 916661395, 180504391, 9268777, 61073, 1;
		

Crossrefs

Programs

  • Maple
    A176490 := proc(n,k)
        A008292(n+1,k+1)+A060187(n+1,k+1)-1 ;
    end proc: # R. J. Mathar, Jun 16 2015
  • Mathematica
    (*A060187*)
    p[x_, n_] = (1 - x)^(n + 1)*Sum[(2*k + 1)^n*x^k, {k, 0, Infinity}];
    f[n_, m_] := CoefficientList[FullSimplify[ExpandAll[p[x, n]]], x][[m + 1]];
    << DiscreteMath`Combinatorica`;
    t[n_, m_, 0] := Binomial[n, m];
    t[n_, m_, 1] := Eulerian[1 + n, m];
    t[n_, m_, 2] := f[n, m];
    t[n_, m_, q_] := t[n, m, q] = t[n, m, q - 2] + t[n, m, q - 3] - 1;
    Table[Flatten[Table[Table[t[n, m, q], {m, 0, n}], {n, 0, 10}]], {q, 0, 10}]

A065826 Triangle with T(n,k) = k*E(n,k) where E(n,k) are Eulerian numbers A008292.

Original entry on oeis.org

1, 1, 2, 1, 8, 3, 1, 22, 33, 4, 1, 52, 198, 104, 5, 1, 114, 906, 1208, 285, 6, 1, 240, 3573, 9664, 5955, 720, 7, 1, 494, 12879, 62476, 78095, 25758, 1729, 8, 1, 1004, 43824, 352936, 780950, 529404, 102256, 4016, 9, 1, 2026, 143520, 1820768, 6551770, 7862124, 3186344, 382720, 9117, 10
Offset: 1

Views

Author

Henry Bottomley, Dec 06 2001

Keywords

Comments

Row sums are (n+1)!/2, i.e., A001710 offset, implying that if n balls are put at random into n boxes, the expected number of boxes with at least one ball is (n+1)/2 and the expected number of empty boxes is (n-1)/2.
T(n,k) is the number of permutations of {1,2,...,n+1} that start with an ascent and that have k-1 descents. - Ira M. Gessel, May 02 2017

Examples

			Rows start:
  1;
  1,   2;
  1,   8,     3;
  1,  22,    33,     4;
  1,  52,   198,   104,     5;
  1, 114,   906,  1208,   285,     6;
  1, 240,  3573,  9664,  5955,   720,    7;
  1, 494, 12879, 62476, 78095, 25758, 1729, 8;
  etc.
		

Crossrefs

Cf. A008292.

Programs

  • GAP
    Flat(List([1..10],n->List([1..n],k->Sum([0..k],j->k*(-1)^j*(k-j)^n*Binomial(n+1,j))))); # Muniru A Asiru, Mar 09 2019
  • Maple
    T:=(n,k)->add(k*(-1)^j*(k-j)^n*binomial(n+1,j),j=0..k): seq(seq(T(n,k),k=1..n),n=1..10); # Muniru A Asiru, Mar 09 2019
  • Mathematica
    Array[Range[Length@ #] # &@ CoefficientList[(1 - x)^(# + 1)*PolyLog[-#, x]/x, x] &, 10] (* Michael De Vlieger, Sep 24 2018, after Vaclav Kotesovec at A008292 *)

Formula

T(n, k) = k*(a(n-1, k) + a(n-1, k-1)*(n-k+1)/(k-1)) [with T(n, 1) = 1] = Sum_{j=0..k} k*(-1)^j*(k-j)^n*binomial(n+1, j).
E.g.f.: (exp(x*(1-t)) - 1 - x*(1-t))/((1-t)*(1 - t*exp(x*(1-t)))). - Ira M. Gessel, May 02 2017

A087674 Value of the n-th Eulerian polynomial (cf. A008292) evaluated at x=-2.

Original entry on oeis.org

1, 1, -1, -3, 15, 21, -441, 477, 19935, -101979, -1150281, 14838957, 60479055, -2328851979, 3529587879, 403992301437, -3333935426625, -72778393505979, 1413503392326039, 10851976875907917, -554279405351601105, 713848745428080021
Offset: 0

Views

Author

Vladeta Jovovic, Sep 26 2003

Keywords

Examples

			G.f. = 1 + x - x^2 - 3*x^3 + 15*x^4 + 21*x^5 - 441*x^6 + 477*x^7 + 19935*x^8 + ... - _Michael Somos_, Aug 27 2018
		

Crossrefs

Programs

  • Mathematica
    Table[-3^(n+1)/2*PolyLog[-n, -2], {n, 0, 21}] (* Jean-François Alcover, Apr 26 2013 *)
    a[ n_] := If[ n < 0, 0, n! 3/2 SeriesCoefficient[ 1 / (1 + Exp[-3 x] / 2), {x, 0, n}]]; (* Michael Somos, Aug 27 2018 *)
  • PARI
    {a(n)=polcoeff(sum(m=0,n,m!*x^m/prod(k=1,m,1+3*k*x+x*O(x^n))),n)} /* Paul D. Hanna, Jul 20 2011 */
    
  • PARI
    x='x+O('x^66); Vec(serlaplace( 3*exp(x)/(2*exp(x)+exp(-2*x)) )) \\ Joerg Arndt, Apr 21 2013
    
  • PARI
    {a(n) = if( n<0, 0, n! * 3/2 * polcoeff( 1 / (1 + exp( -3*x + x * O(x^n)) / 2), n))}; /* Michael Somos, Aug 27 2018 */

Formula

a(n) = -3^(n+1)/2*polylog(-n, -2).
E.g.f.: 3*exp(x)/(2*exp(x)+exp(-2*x)).
O.g.f.: Sum_{n>=0} n! * x^n / Product_{k=1..n} (1 + 3*k*x). [Paul D. Hanna, Jul 20 2011]
G.f.: 1/Q(0), where Q(k)= 1 - x*(k+1)/(1 + x*(2*k+2)/Q(k+1)); (continued fraction). - Sergei N. Gladkovskii, May 20 2013
a(n) = (-1)^n * A212846(n). - Michael Somos, Aug 27 2018
a(n) = Sum_{k=0..n} Stirling2(n,k) * k! * (-3)^(n-k). - Ilya Gutkovskiy, Jun 08 2022

Extensions

More terms from Paul D. Hanna, Jul 20 2011

A104098 a(n) = Sum_{k=1..n} binomial(n-1, k-1)*A008292(n, k) for n >= 1.

Original entry on oeis.org

1, 2, 10, 68, 606, 6612, 85492, 1277096, 21641590, 410144180, 8595133548, 197346180792, 4926442358124, 132847425483528, 3848398710032616, 119187270233781456, 3929892162743796390, 137444081992905303540, 5082053733073190713660, 198081684441819323760920
Offset: 1

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Author

Paul D. Hanna, Mar 29 2006

Keywords

Examples

			   1 = 1*1
   2 = 1*1 +  1*1
  10 = 1*1 +  2*4 + 1*1
  68 = 1*1 + 3*11 + 3*11 + 1*1
  ...
		

Crossrefs

Programs

  • Maple
    a := n -> local k; add(binomial(n - 1, k - 1) * combinat:-eulerian1(n, k - 1), k = 1..n): seq(a(n), n = 1..20);  # Peter Luschny, Oct 29 2023
  • Mathematica
    Table[Sum[Binomial[n-1,k-1] * Sum[(-1)^j * (k-j)^n * Binomial[n+1,j], {j, 0, k}], {k, 1, n}], {n, 1, 20}] (* Vaclav Kotesovec, Oct 09 2020 *)

Formula

a(n) ~ sqrt(3) * 2^(n-1) * n^n / exp(n). - Vaclav Kotesovec, Oct 09 2020, modified for offset 1, Oct 29 2023

Extensions

Offset changed by Georg Fischer, Oct 29 2023
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