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 1-10 of 16 results. Next

A059968 Number of 10-ary trees.

Original entry on oeis.org

1, 1, 10, 145, 2470, 46060, 910252, 18730855, 397089550, 8612835715, 190223180840, 4263421511271, 96723482198980, 2216905597676000, 51256802757808320, 1194060413809070710, 27999654303202465310, 660370070571422998410, 15654733143626084944150
Offset: 0

Views

Author

Claude Lenormand (claude.lenormand(AT)free.fr), Mar 05 2001

Keywords

Comments

From Wolfdieter Lang, Feb 06 2020: (Start)
Ninth column of triangle A062993 (without leading zeros). A Pfaff-Fuss or 10-Raney sequence.
a(n), n>=1, enumerates 10-ary trees (rooted, ordered, incomplete) with n vertices (including the root).
See Graham et al., Hilton and Pedersen, Hoggat and Bicknell, Frey and Sellers references given in A062993. (End)
This is instance k = 10 of the generalized Catalan family {C(k, n)}A130564%20-%20_Wolfdieter%20Lang">{n>=0} given in a comment of A130564 - _Wolfdieter Lang, Feb 05 2024

Examples

			There are a(2)=10 10-ary trees (vertex degree <=10 and 10 possible branchings) with 2 vertices (one of them the root). Adding one more branch (one more vertex) to these 10 trees yields 10*10+binomial(10,2)=145=a(3) such trees. - _Wolfdieter Lang_, Sep 14 2007.
		

References

  • G. Pólya and G. Szegő, Problems and Theorems in Analysis, Springer-Verlag, Heidelberg, New York, 2 vols., 1972, Vol. 1, problem 211, p. 146 with solution on p. 348.

Crossrefs

Related algebraic sequences concerning trees: strictly k-ary trees (A000108: s=x+s^2, A001263: s=(x, y)+(x, s)+(s, y)+(s, s))), (A001764: s=x+s^3), (A002293: s=x+s^4), (A002294: s=x+s^5), (A002295: s=x+s^6), (A002296: s=x+s^7), (A007556: s=x+s^8), at most k-ary trees (A001006: s=x+xs+xs^2), (A036765-A036769, s=x+xs^2....+xs^k, k=3, 4, 5, 6, 7).
Cf. A130564.

Programs

  • Maple
    seq(binomial(10*k+1, k)/(9*k+1), k=0..30);
    n:=30:G:=series(RootOf(g = 1+x*g^10, g), x=0, n+1):seq(coeff(G, x, k), k=0..n); # Robert FERREOL, Apr 01 2015
  • Mathematica
    a[n_] := Binomial[10n, n]/(9n+1);
    a /@ Range[0, 25] (* Jean-François Alcover, Jan 17 2020 *)

Formula

G.f. A(x) satisfies: A = x + A^10.
a(n) = binomial(k*n, n)/((k-1)*n+1), for k=10.
Recurrence: a(0) = 1; a(n) = Sum_{i1+i2+..i10=n-1} a(i1)*a(i2)*...*a(i10) for n>=1. - Robert FERREOL, Apr 01 2015
From Wolfdieter Lang, Feb 06 2020: (Start)
a(n) = A062993(n+8, 8). [Corrected by Robert FERREOL, Apr 01 2015]
G.f.: RootOf((_Z^10)*x-_Z+1) (Maple notation, from ECS, see links for A007556).
G.f.: hypergeometric([1, 2, 3, 4, 5, 6, 7, 8, 9]/10, [2, 3, 4, 5, 6, 7, 8, 10]/9, (10^10/9^9)*x),
E.g.f.: hypergeometric([1, 2, 3, 4, 5, 6, 7, 8, 9]/10, [2, 3, 4, 5, 6, 7, 8, 9, 10]/9, (10^10/9^9)*x).
For other family members see the crossreferences.
(End)
D-finite with recurrence 81*n*(9*n-7)*(9*n-5)*(3*n-1)*(9*n-1)*(9*n+1)*(3*n-2)*(9*n-4)*(9*n-2)*a(n) -800*(10*n-9)*(5*n-4)*(10*n-7)*(5*n-3)*(2*n-1)*(5*n-2)*(10*n-3)*(5*n-1)*(10*n-1)*a(n-1)=0. - R. J. Mathar, Mar 21 2022
a(n) ~ (10^10/9^9)^n*sqrt(10/(2*Pi*(9*n)^3)). - Robert A. Russell, Jul 15 2024
G.f. A(x) satisfies A(x) = 1/A(-x*A(x)^19). - Seiichi Manyama, Jun 16 2025

Extensions

More terms from James Sellers, Mar 15 2001
a(0)=1 inserted by Alois P. Heinz, Jan 17 2020
A062744 merged into this sequence by Wolfdieter Lang, Feb 06 2020

A251592 Triangle of coefficients of polynomials P(n,t) related to the Mittag-Leffler function, where P(n,t) = Product_{k=0..n-2} n*t-k.

Original entry on oeis.org

1, 0, 2, 0, -3, 9, 0, 8, -48, 64, 0, -30, 275, -750, 625, 0, 144, -1800, 7560, -12960, 7776, 0, -840, 13426, -77175, 204085, -252105, 117649, 0, 5760, -112896, 831488, -3010560, 5734400, -5505024, 2097152, 0, -45360, 1058508, -9573228
Offset: 1

Views

Author

Jean-François Alcover, Dec 05 2014

Keywords

Comments

Second column (unsigned) 2, 3, 8, 30, 144, ... is A001048.
Diagonal 1, 2, 9, 64, 625, 7776, ... is A000169.

Examples

			Triangle begins :
  1;
  0,   2;
  0,  -3,     9;
  0,   8,   -48,   64;
  0, -30,   275, -750,    625;
  0, 144, -1800, 7560, -12960, 7776;
  ...
		

References

  • R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, Addison-Wesley, Reading, MA, 2nd ed. 1998

Crossrefs

Cf. A000169, A001048, A156136, A000108 (B_2(x)), A001764 (B_3(x)), A002293 (B_4(x)), A002294 (B_5(x)), A002295 (B_6(x)), A002296 (B_7(x)), A007556 (B_8(x)), A062994 (B_9(x)), A059968 (B_10(x)), A230388 (B_11(x)), A139526, A260687.

Programs

  • Mathematica
    P[n_, t_] := Product[n*t - k, {k, 0, n-2}]; row[n_] := CoefficientList[P[n, t], t]; Table[row[n], {n, 1, 10}] // Flatten

Formula

P(n,t) = (n-1)!*binomial(n*t, n-1).
From Peter Bala, Nov 15 2015: (Start)
E.g.f. (with constant term 1): B_t(x) = Sum_{n >= 0} 1/(n*t + 1)*binomial(n*t + 1,n)*x^n = 1 + x + 2*t*x^2/2! + 3*t(3*t - 1)*x^3/3! + 4*t*(4*t - 1)*(4*t - 2)*x^4/4! + ... is the generalized binomial series of Lambert. See Graham et al., Section 5.4 and Section 7.5.
In the notation of the Bala link, B_t(x) = I^t(1 + x) where I^t is a fractional inversion operator. B_(1+t)(x) is the e.g.f. for A260687.
B_t(x) = 1 + x*B_t(x)^t.
For complex r, B_t(x)^r = Sum_{n >= 0} r/(n*t + r)*binomial(n*t + r,n)*x^n.
log (B_t(x)) = Sum_{n >= 1} 1/(n*t)*binomial(n*t,n)*x^n.
B_2(x) is the o.g.f. for the Catalan numbers A000108. B_t(x) for t = 3,4,5,... gives the o.g.f. for various Fuss-Catalan sequences. See the cross references. (End)

A062993 A triangle (lower triangular matrix) composed of Pfaff-Fuss (or Raney) sequences.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 5, 3, 1, 1, 14, 12, 4, 1, 1, 42, 55, 22, 5, 1, 1, 132, 273, 140, 35, 6, 1, 1, 429, 1428, 969, 285, 51, 7, 1, 1, 1430, 7752, 7084, 2530, 506, 70, 8, 1, 1, 4862, 43263, 53820, 23751, 5481, 819, 92, 9
Offset: 0

Views

Author

Wolfdieter Lang, Jul 12 2001

Keywords

Comments

The column sequences (without leading zeros) appear in eq.(7.66), p. 347 of the Graham et al. reference, in Th. 0.3, p. 66, of Hilton and Pedersen reference, as first columns of the S-triangles in the Hoggatt and Bicknell reference and in eq. 5 of the Frey and Sellers reference. They are also called m-Raney (here m=k+2) or Fuss-Catalan sequences (see Graham et al. for reference). For the history and the name Pfaff-Fuss see Brown reference, p. 975. PF(n,m) := binomial(m*n+1,n)/(m*n+1), m >= 2.
Also called generalized Catalan numbers.

Examples

			The triangle a(n, k) begins:
n\k     0      1      2      3     4     5    6   7  8  9 10 ...
0:      1
1:      1      1
2:      2      1      1
3:      5      3      1      1
4:     14     12      4      1     1
5:     42     55     22      5     1     1
6:    132    273    140     35     6     1    1
7:    429   1428    969    285    51     7    1   1
8:   1430   7752   7084   2530   506    70    8   1  1
9:   4862  43263  53820  23751  5481   819   92   9  1  1
10: 16796 246675 420732 231880 62832 10472 1240 117 10  1  1
... Reformatted by _Wolfdieter Lang_, Feb 06 2020
		

References

  • R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 2nd. ed., 1994.

Crossrefs

Reflected version of A070914.
Columns k=0..9 (without leading zeros) give sequences A000108 (Catalan), A001764, A002293, A002294, A002295, A002296, A007556, A062994, A059968, A230388.

Programs

  • Mathematica
    a[n_, k_] = Binomial[(k+2)*(n-k), n-k]/((k+1)*(n-k) + 1);
    Flatten[Table[a[n, k], {n, 0, 9}, {k, 0, n}]][[1 ;; 53]]
    (* Jean-François Alcover, May 27 2011, after formula *)

Formula

a(n, k) = binomial((k+2)*(n-k), n-k)/((k+1)*(n-k)+1) = PF(n-k, k+2) if n-k >= 0, otherwise 0.
G.f. for column k: A(k, x) := x^k*RootOf(_Z^(k+2)*x-_Z+1) (Maple notation, from ECS, see links for column sequences and Graham et al. reference eq.(5.59) p. 200 and p. 349).

A234868 a(n) = 2*binomial(11*n+2,n)/(11*n+2).

Original entry on oeis.org

1, 2, 23, 374, 7095, 146916, 3219216, 73386170, 1722567143, 41352865400, 1010607195741, 25058477434562, 628845572227600, 15941429819185752, 407626109449551300, 10501154649486399096, 272294680440574235015, 7101160966497659412010, 186134223613500403098396
Offset: 0

Views

Author

Tim Fulford, Jan 01 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p=11, r=2; also, g.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r.

Crossrefs

Programs

  • Magma
    [2*Binomial(11*n+2,n)/(11*n+2): n in [0..30]]; // Vincenzo Librandi, Jan 01 2014
    
  • Mathematica
    Table[2 Binomial[11 n + 2, n]/(11 n + 2), {n, 0, 30}] (* Vincenzo Librandi, Jan 01 2014 *)
  • PARI
    a(n) = 2*binomial(11*n+2,n)/(11*n+2)
    for(n=0,20, print(a(n))) \\ Sequence
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/2))^2+x*O(x^n)); polcoeff(B, n)}
    for (n=0,20, print(a(n))) \\ Generating Function
    
  • Sage
    [2*binomial(11*n+2,n)/(11*n+2) for n in range(20)] # F. Chapoton; Apr 29 2020

Formula

a(n) = 2*binomial(11*n+1,n-1)/n for n>0, a(0)=1. [Bruno Berselli, Jan 19 2014]

A234870 4*binomial(11*n+4,n)/(11*n+4).

Original entry on oeis.org

1, 4, 50, 840, 16215, 339416, 7492342, 171714400, 4046995095, 97464474800, 2388021782916, 59337354111464, 1491714713034000, 37872300445759440, 969656048236053850, 25008097347083474496, 649098691321081570855, 16942574600154870074100
Offset: 0

Views

Author

Tim Fulford, Jan 01 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p=11, r=4.

Crossrefs

Programs

  • Magma
    [4*Binomial(11*n+4,n)/(11*n+4): n in [0..30]]; // Vincenzo Librandi, Jan 01 2014
  • Mathematica
    Table[4 Binomial[11 n + 4, n]/(11 n + 4), {n, 0, 40}] (* Vincenzo Librandi, Jan 01 2014 *)
  • PARI
    a(n) = 4*binomial(11*n+4,n)/(11*n+4);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/4))^4+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, with p=11, r=4.

A234873 7*binomial(11*n+7,n)/(11*n+7).

Original entry on oeis.org

1, 7, 98, 1729, 34300, 730597, 16323468, 377447148, 8956384437, 216859117475, 5336519142108, 133078780790725, 3355661187741408, 85414540549845934, 2191753761503128400, 56636249639625891144, 1472525237190942707955
Offset: 0

Views

Author

Tim Fulford, Jan 01 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p=11, r=7.

Crossrefs

Programs

  • Magma
    [7*Binomial(11*n+7,n)/(11*n+7): n in [0..30]]; // Vincenzo Librandi, Jan 01 2014
  • Mathematica
    Table[7 Binomial[11 n + 7, n]/(11 n + 7), {n, 0, 30}] (* Vincenzo Librandi, Jan 01 2014 *)
  • PARI
    a(n) = 7*binomial(11*n+7,n)/(11*n+7);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/7))^7+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, with p=11, r=7.

A234869 3*binomial(11*n+3,n)/(11*n+3).

Original entry on oeis.org

1, 3, 36, 595, 11385, 237006, 5212064, 119126865, 2801765835, 67365151700, 1648369018296, 40914062713953, 1027625691201200, 26069631471224820, 667024542735629400, 17193066926119888716, 446028709678732029135, 11636873606948476550895
Offset: 0

Views

Author

Tim Fulford, Jan 01 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p=11, r=3.

Crossrefs

Programs

  • Magma
    [3*Binomial(11*n+3,n)/(11*n+3): n in [0..30]]; // Vincenzo Librandi, Jan 01 2014
  • Mathematica
    Table[3 Binomial[11 n + 3, n]/(11 n + 3), {n, 0, 30}] (* Vincenzo Librandi, Jan 01 2014 *)
  • PARI
    a(n) = 3*binomial(11*n+3,n)/(11*n+3);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/3))^3+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, with p=11, r=3.

A234871 a(n) = 5*binomial(11*n+5,n)/(11*n+5).

Original entry on oeis.org

1, 5, 65, 1110, 21620, 455126, 10085845, 231814440, 5475346305, 132090011900, 3240886705386, 80621405042750, 2028732009726240, 51548408940061460, 1320738410528418175, 34083616545621832176, 885134579074202142075, 23114512490211287029665
Offset: 0

Views

Author

Tim Fulford, Jan 01 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p=11, r=5.

Crossrefs

Programs

  • Magma
    [5*Binomial(11*n+5,n)/(11*n+5): n in [0..30]]; // Vincenzo Librandi, Jan 01 2014
  • Mathematica
    Table[5 Binomial[11 n + 5, n]/(11 n + 5), {n, 0, 40}] (* Vincenzo Librandi, Jan 01 2014 *)
  • PARI
    a(n) = 5*binomial(11*n+5,n)/(11*n+5);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/5))^5+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, with p=11, r=5.

A234872 a(n) = 6*binomial(11*n+6,n)/(11*n+6).

Original entry on oeis.org

1, 6, 81, 1406, 27636, 585162, 13019909, 300138696, 7105216833, 171717015470, 4219267597578, 105085831400550, 2647012241261856, 67316157557021436, 1726006087183713615, 44570883175043934384, 1158139943222389790715
Offset: 0

Views

Author

Tim Fulford, Jan 01 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p=11, r=6.

Crossrefs

Programs

  • Magma
    [6*Binomial(11*n+6,n)/(11*n+6): n in [0..30]]; // Vincenzo Librandi, Jan 01 2014
  • Mathematica
    Table[6 Binomial[11 n + 6, n]/(11 n + 6), {n, 0, 40}] (* Vincenzo Librandi, Jan 01 2014 *)
  • PARI
    a(n) = 6*binomial(11*n+6,n)/(11*n+6);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/6))^6+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, with p=11, r=6.
a(n) ~ 3*4^(-3-5*n)*5^(-13/2-10*n)*11^(11/2+11*n)/(n^(3/2)*sqrt(Pi)). - Stefano Spezia, Aug 23 2025

A235339 a(n) = 9*binomial(11*n+9,n)/(11*n+9).

Original entry on oeis.org

1, 9, 135, 2460, 49725, 1072197, 24163146, 562311720, 13409091540, 325949656825, 8046743477058, 201198155083200, 5084704634041305, 129673310477725350, 3332952595603387800, 86250038091202771344, 2245329811618166111985
Offset: 0

Views

Author

Tim Fulford, Jan 06 2014

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), this is the case p = 11, r = 9.

Crossrefs

Programs

  • Magma
    [9*Binomial(11*n+9, n)/(11*n+9): n in [0..30]];
  • Mathematica
    Table[9 Binomial[11 n + 9, n]/(11 n + 9), {n, 0, 30}]
  • PARI
    a(n) = 9*binomial(11*n+9,n)/(11*n+9);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(11/9))^9+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, here p = 11, r = 9.
O.g.f. A(x) = 1/x * series reversion (x/C(x)^9), where C(x) is the o.g.f. for the Catalan numbers A000108. A(x)^(1/9) is the o.g.f. for A230388. - Peter Bala, Oct 14 2015
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