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 12 results. Next

A118971 a(n) = binomial(5*n+3,n)/(n+1).

Original entry on oeis.org

1, 4, 26, 204, 1771, 16380, 158224, 1577532, 16112057, 167710664, 1772645420, 18974357220, 205263418941, 2240623268512, 24648785802336, 272994644359580, 3041495503591365, 34064252968167180, 383302465665133014
Offset: 0

Views

Author

Paul Barry, May 07 2006

Keywords

Comments

A quadrisection of A118968.
For n >= 1, a(n-1) is the number of lattice paths from (0,0) to (4n,n) using only the steps (1,0) and (0,1) and which stay strictly below the line y = x/4 except at the path's endpoints. - Lucas A. Brown, Aug 21 2020
This is instance k = 4 of the family {c(k, n+1)}A130564.%20-%20_Wolfdieter%20Lang">{n>=0} given in a comment in A130564. - _Wolfdieter Lang, Feb 04 2024

Crossrefs

Cf. A000108, A006013, A006632, A130564, A130565, A234466, A234513, A234573, A235340 (members of the same family).

Programs

  • Mathematica
    Table[4*Binomial[5n+3,n]/(4n+4),{n,0,30}] (* Harvey P. Dale, Apr 09 2012 *)

Formula

G.f.: If the inverse series of y*(1-y)^4 is G(x) then A(x)=G(x)/x.
D-finite with recurrence 8*(4*n+1)*(2*n+1)*(4*n+3)*(n+1)*a(n) -5*(5*n+1)*(5*n+2)*(5*n+3)*(5*n-1)*a(n-1)=0. - R. J. Mathar, Nov 26 2012
a(n) = (4/5)*binomial(5*(n+1),n+1)/(5*(n+1)-1). - Bruno Berselli, Jan 17 2014
E.g.f.: 4F4(4/5,6/5,7/5,8/5; 5/4,3/2,7/4,2; 3125*x/256). - Ilya Gutkovskiy, Jan 23 2018
G.f.: 5F4([4,5,6,7,8]/5, [5,6,7,8]/4; (5^5/4^4)*x) = (4/(5*x))*(1 - 4F3([-1,1,2,3]/5, [1,2,3]/4; (5^5/4^4)*x)). - Wolfdieter Lang, Feb 15 2024

A130564 Member k=5 of a family of generalized Catalan numbers.

Original entry on oeis.org

1, 5, 40, 385, 4095, 46376, 548340, 6690585, 83615350, 1064887395, 13770292256, 180320238280, 2386316821325, 31864803599700, 428798445360120, 5809228810425801, 79168272296871450, 1084567603590147950
Offset: 1

Views

Author

Wolfdieter Lang, Jul 13 2007

Keywords

Comments

The generalized Catalan numbers C(k,n):= binomial(k*n+1,n)/(k*n+1) become for negative k=-|k|, with |k|>=2, ((-1)^(n-1))*binomial((|k|+1)*n-2,n)/(|k|*n-1), n>=0.
The family c(k,n):=binomial((k+1)*n-2,n)/(k*n-1), n>=1, has the members A000108, A006013, A006632, A118971 for k=1,2,3,4, respectively (but the offset there is 0).
The members of the C(k,n) family for positive k are: A000012 (powers of 1), A000108, A001764, A002293, A002294, A002295, A002296, A007556, A062994, for k=1..9.

References

  • Ronald L. Graham, Donald E. Knuth and Oren Patashnik, Concrete Mathematics, Addison-Wesley, Reading, MA, 2nd ed. 1994, pp. 200, 363.

Crossrefs

Programs

  • Mathematica
    Rest@ CoefficientList[InverseSeries[Series[y (1 - y)^5, {y, 0, 18}], x], x] (* Michael De Vlieger, Oct 13 2019 *)

Formula

a(n) = binomial((k+1)*n-2,n)/(k*n-1), with k=5.
G.f.: inverse series of y*(1-y)^5.
a(n) = (5/6)*binomial(6*n,n)/(6*n-1). [Bruno Berselli, Jan 17 2014]
From Wolfdieter Lang, Feb 06 2020: (Start)
G.f.: (5/6)*(1 - hypergeom([-1, 1, 2, 3, 4]/6, [1, 2, 3, 4]/5,(6^6/5^5)*x)).
E.g.f.: (5/6)*(1 - hypergeom([-1, 1, 2, 3, 4]/6, [1, 2, 3, 4, 5]/5,(6^6/5^5)*x)). (End)
D-finite with recurrence 5*n*(5*n-4)*(5*n-3)*(5*n-2)*(5*n-1)*a(n) -72*(6*n-7)*(3*n-1)*(2*n-1)*(3*n-2)*(6*n-5)*a(n-1)=0. - R. J. Mathar, May 07 2021

A229963 a(n) = 11*binomial(10*n + 11, n)/(10*n + 11) .

Original entry on oeis.org

1, 11, 165, 2860, 53900, 1072797, 22188859, 472214600, 10273141395, 227440759700, 5107663394691, 116068178638776, 2664012608972000, 61668340817988135, 1438101958237201950, 33753007927148177360, 796704536753910327114
Offset: 0

Views

Author

Tim Fulford, Oct 04 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(n*p + r,n)/(n*p + r), where p = 10, r = 11.

Crossrefs

Cf. A000245 (k = 3), A006629 (k = 4), A196678 (k = 5), A233668 (k = 6), A233743 (k = 7), A233835 (k = 8), A234467 (k = 9), A232265 (k = 10).

Programs

  • Magma
    [11*Binomial(10*n+11,n)/(10*n+11) : n in [0..20]]; // Vincenzo Librandi, Jan 10 2014
  • Mathematica
    Table[11/(10 n + 11) Binomial[10 n + 11, n], {n, 0, 40}] (* Vincenzo Librandi, Jan 10 2014 *)
  • PARI
    a(n) = 11*binomial(10*n+11,n)/(10*n+11);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(10/11))^11+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: A(x) = {1 + x*A(x)^(p/r)}^r, where p = 10, r = 11.
From _Peter Bala, Oct 16 2015: (Start)
O.g.f. A(x) = 1/x * series reversion (x*C(-x)^11), where C(x) = (1 - sqrt(1 - 4*x))/(2*x) is the o.g.f. for the Catalan numbers A000108. See cross-references for other Fuss-Catalan sequences with o.g.f. 1/x * series reversion (x*C(-x)^k), k = 3 through 11.
A(x)^(1/11) is the o.g.f. for A059968. (End)
D-finite with recurrence: 81*n*(9*n+11)*(9*n+4)*(3*n+2)*(9*n+8)*(9*n+10)*(3*n+1)*(9*n+5)*(9*n+7)*a(n) -800*(10*n+1)*(5*n+1)*(10*n+3)*(5*n+2)*(2*n+1)*(5*n+3)*(10*n+7)*(5*n+4)*(10*n+9)*a(n-1)=0. - R. J. Mathar, Feb 21 2020

Extensions

Corrected by Vincenzo Librandi, Jan 10 2014

A234571 a(n) = 4*binomial(10*n+8,n)/(5*n+4).

Original entry on oeis.org

1, 8, 108, 1776, 32430, 632016, 12876864, 270964320, 5843355957, 128462407840, 2868356980060, 64869895026144, 1482877843096650, 34207542810153216, 795318309360948240, 18617396126132233920, 438423206616057162258, 10379232525028947311160, 246878659984195222962220
Offset: 0

Views

Author

Tim Fulford, Dec 28 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), where p = 10, r = 8.

Crossrefs

Programs

  • Magma
    [4*Binomial(10*n+8, n)/(5*n+4): n in [0..30]];
  • Mathematica
    Table[4 Binomial[10 n + 8, n]/(5 n + 4), {n, 0, 30}]
  • PARI
    a(n) = 4*binomial(10*n+8,n)/(5*n+4);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(5/4))^8+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, where p = 10, r = 8.
O.g.f. A(x) = 1/x * series reversion (x/C(x)^8), where C(x) is the o.g.f. for the Catalan numbers A000108. A(x)^(1/8) is the o.g.f. for A059968. - Peter Bala, Oct 14 2015

A234525 Binomial(10*n+2,n)/(5*n+1).

Original entry on oeis.org

1, 2, 21, 310, 5330, 99960, 1983049, 40919714, 869304150, 18885977110, 417663940540, 9371084905962, 212791660837756, 4880918206648000, 112925143575796455, 2632162372046272660, 61752662230350642670, 1457074607325333325524
Offset: 0

Views

Author

Tim Fulford, Dec 27 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), where p=10, r=2.

Crossrefs

Programs

  • Magma
    [Binomial(10*n+2, n)/(5*n+1): n in [0..30]]; // Vincenzo Librandi, Dec 27 2013
  • Mathematica
    Table[Binomial[10 n + 2, n]/(5 n + 1), {n, 0, 40}] (* Vincenzo Librandi, Dec 27 2013 *)
  • PARI
    a(n) = binomial(10*n+2,n)/(5*n+1);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^5)^2+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, where p=10, r=2.
a(n) = 2*binomial(10n+1,n-1)/n for n>0, a(0)=1. [Bruno Berselli, Jan 19 2014]

A251580 E.g.f.: exp(10*x*G(x)^9) / G(x)^9 where G(x) = 1 + x*G(x)^10 is the g.f. of A059968.

Original entry on oeis.org

1, 1, 10, 280, 13960, 1023760, 99935200, 12226859200, 1801725932800, 310890328768000, 61516405597830400, 13735605457885312000, 3416919943285809280000, 937247149729410729472000, 281051240591439955878400000, 91474949907165746668607488000, 32117399444469103248129863680000
Offset: 0

Views

Author

Paul D. Hanna, Dec 06 2014

Keywords

Comments

In general, Sum_{k=0..n} m^k * n!/k! * binomial(m*n-k-m, n-k) * (k-1)/(n-1) is for m>1 asymptotic to m^(m*(n-1)-1/2) / (m-1)^((m-1)*(n-1)-1/2) * n^(n-2) / exp(n-1). - Vaclav Kotesovec, Dec 07 2014

Examples

			E.g.f.: A(x) = 1 + x + 10*x^2/2! + 280*x^3/3! + 13960*x^4/4! + 1023760*x^5/5! +...
such that A(x) = exp(10*x*G(x)^9) / G(x)^9
where G(x) = 1 + x*G(x)^10 is the g.f. of A059968:
G(x) = 1 + x + 10*x^2 + 145*x^3 + 2470*x^4 + 46060*x^5 + 910252*x^6 +...
Note that
A'(x) = exp(10*x*G(x)^9) = 1 + 10*x + 280*x^2/2! + 13960*x^3/3! +...
LOGARITHMIC DERIVATIVE.
The logarithm of the e.g.f. begins:
log(A(x)) = x + 9*x^2/2 + 252*x^3/3 + 12654*x^4/4 + 933984*x^5/5 +...
and so A'(x)/A(x) = G(x)^9.
TABLE OF POWERS OF E.G.F.
Form a table of coefficients of x^k/k! in A(x)^n as follows.
n=1: [1, 1,  10,  280,  13960,  1023760,   99935200,  12226859200, ...];
n=2: [1, 2,  22,  620,  30760,  2243120,  217911520,  26556406400, ...];
n=3: [1, 3,  36, 1026,  50760,  3683880,  356283360,  43256151360, ...];
n=4: [1, 4,  52, 1504,  74344,  5374240,  517647520,  62621962240, ...];
n=5: [1, 5,  70, 2060, 101920,  7344920,  704861200,  84980501600, ...];
n=6: [1, 6,  90, 2700, 133920,  9629280,  921060720, 110691813600, ...];
n=7: [1, 7, 112, 3430, 170800, 12263440, 1169680960, 140152067440, ...];
n=8: [1, 8, 136, 4256, 213040, 15286400, 1454475520, 173796462080, ...]; ...
in which the main diagonal begins (see A251587):
[1, 2, 36, 1504, 101920, 9629280, 1169680960, 173796462080, ...]
and is given by the formula:
[x^n/n!] A(x)^(n+1) = 10^(n-8) * (n+1)^(n-9) * (4782969*n^8 + 50309748*n^7 + 237013938*n^6 + 655232760*n^5 + 1166624361*n^4 + 1374998212*n^3 + 1051760172*n^2 + 479277840*n + 100000000) for n>=0.
		

Crossrefs

Programs

  • Mathematica
    Flatten[{1,1,Table[Sum[10^k * n!/k! * Binomial[10*n-k-10, n-k] * (k-1)/(n-1),{k,0,n}],{n,2,20}]}] (* Vaclav Kotesovec, Dec 07 2014 *)
  • PARI
    {a(n) = local(G=1);for(i=1,n, G = 1 + x*G^10 +x*O(x^n)); n!*polcoeff( exp(10*x*G^9) / G^9, n)}
    for(n=0, 20, print1(a(n), ", "))
    
  • PARI
    {a(n) = if(n==0, 1, sum(k=0, n, 10^k * n!/k! * binomial(10*n-k-10,n-k)*if(n==1,1/10,(k-1)/(n-1)) ))}
    for(n=0, 20, print1(a(n), ", "))

Formula

Let G(x) = 1 + x*G(x)^10 be the g.f. of A059968, then the e.g.f. A(x) of this sequence satisfies:
(1) A'(x)/A(x) = G(x)^9.
(2) A'(x) = exp(10*x*G(x)^9).
(3) A(x) = exp( Integral G(x)^9 dx ).
(4) A(x) = exp( Sum_{n>=1} A234573(n-1)*x^n/n ), where A234573(n-1) = binomial(10*n-2,n)/(9*n-1).
(5) A(x) = F(x/A(x)) where F(x) is the e.g.f. of A251590.
(6) A(x) = Sum_{n>=0} A251590(n)*(x/A(x))^n/n! and
(7) [x^n/n!] A(x)^(n+1) = (n+1)*A251590(n),
where A251590(n) = 10^(n-8) * (n+1)^(n-10) * (4782969*n^8 + 50309748*n^7 + 237013938*n^6 + 655232760*n^5 + 1166624361*n^4 + 1374998212*n^3 + 1051760172*n^2 + 479277840*n + 100000000).
a(n) = Sum_{k=0..n} 10^k * n!/k! * binomial(10*n-k-10, n-k) * (k-1)/(n-1) for n>1.
Recurrence: 81*(3*n-5)*(3*n-4)*(9*n-17)*(9*n-16)*(9*n-14)*(9*n-13)*(9*n-11)*(9*n-10)*(250000*n^8 - 5300000*n^7 + 49332500*n^6 - 263500000*n^5 + 884055975*n^4 - 1909634570*n^3 + 2596659373*n^2 - 2035277286*n + 705468040)*a(n) = 800*(3125000000000*n^17 - 111562500000000*n^16 + 1872125000000000*n^15 - 19618187500000000*n^14 + 143829395937500000*n^13 - 783195370343750000*n^12 + 3281447638218750000*n^11 - 10810863753751875000*n^10 + 28370066880833218750*n^9 - 59681174371832246875*n^8 + 100725400409628775000*n^7 - 135736802338370325750*n^6 + 144424061701272600950*n^5 - 118936947986511839915*n^4 + 73322264536912326596*n^3 - 31942069342168467356*n^2 + 8798129066413437408*n - 1156512281566561920)*a(n-1) + 10000000000*(250000*n^8 - 3300000*n^7 + 19232500*n^6 - 64805000*n^5 + 138543475*n^4 - 193260670*n^3 + 172779013*n^2 - 91243350*n + 22054032)*a(n-2). - Vaclav Kotesovec, Dec 07 2014
a(n) ~ 10^(10*(n-1)-1/2) / 9^(9*(n-1)-1/2) * n^(n-2) / exp(n-1). - Vaclav Kotesovec, Dec 07 2014

A234527 2*binomial(10*n+4,n)/(5*n+2).

Original entry on oeis.org

1, 4, 46, 704, 12341, 234260, 4685898, 97274544, 2075959314, 45262862788, 1003884090440, 22577660493024, 513698787408521, 11802947663348800, 273471432969603198, 6382396843322710560, 149902629054480517590, 3540479504783000035464
Offset: 0

Views

Author

Tim Fulford, Dec 27 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), where p=10, r=4.

Crossrefs

Programs

  • Magma
    [2*Binomial(10*n+4, n)/(5*n+2): n in [0..30]]; // Vincenzo Librandi, Dec 28 2013
  • Mathematica
    Table[2 Binomial[10 n + 4, n]/(5 n + 2), {n, 0, 30}] (* Vincenzo Librandi, Dec 28 2013 *)
  • PARI
    a(n) = 2*binomial(10*n+4,n)/(5*n+2);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(5/2))^4+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, where p=10, r=4.

A234526 3*binomial(10*n+3,n)/(10*n+3).

Original entry on oeis.org

1, 3, 33, 496, 8610, 162435, 3235501, 66959532, 1425658806, 31026962395, 687124547340, 15434728080408, 350818684083868, 8053515040969200, 186457795206547635, 4348790005989493960, 102080931442008205230, 2409777235191897422982
Offset: 0

Views

Author

Tim Fulford, Dec 27 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), where p=10, r=3.

Crossrefs

Programs

  • Magma
    [3*Binomial(10*n+3, n)/(10*n+3): n in [0..30]]; // Vincenzo Librandi, Dec 28 2013
  • Mathematica
    Table[3 Binomial[10 n + 3, n]/(10 n + 3), {n, 0, 30}] (* Vincenzo Librandi, Dec 28 2013 *)
  • PARI
    a(n) = 3*binomial(10*n+3,n)/(10*n+3);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(10/3))^3+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, where p=10, r=3.

A234528 Binomial(10*n+5,n)/(2*n+1).

Original entry on oeis.org

1, 5, 60, 935, 16555, 316251, 6353760, 132321990, 2830853610, 61841702065, 1373736123760, 30935736733230, 704631080073635, 16204866668942000, 375762274309378440, 8775795659568727020, 206241872189050376550, 4873761343609509542490
Offset: 0

Views

Author

Tim Fulford, Dec 27 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), where p=10, r=5.

Crossrefs

Programs

  • Magma
    [Binomial(10*n+5, n)/(2*n+1): n in [0..30]]; // Vincenzo Librandi, Dec 28 2013
  • Mathematica
    Table[Binomial[10 n + 5, n]/(2 n + 1), {n, 0, 30}] (* Vincenzo Librandi, Dec 28 2013 *)
  • PARI
    a(n) = binomial(10*n+5,n)/(2*n+1);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^2)^5+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, where p=10, r=5.

A234529 3*binomial(10*n+6,n)/(5*n+3).

Original entry on oeis.org

1, 6, 75, 1190, 21285, 409266, 8259888, 172593900, 3701885490, 81033954430, 1803028662435, 40658396849388, 927146157991625, 21342995124948000, 495322997953271580, 11576581508367256920, 272239271289546497046, 6437043284012559773100
Offset: 0

Views

Author

Tim Fulford, Dec 27 2013

Keywords

Comments

Fuss-Catalan sequence is a(n,p,r) = r*binomial(np+r,n)/(np+r), where p=10, r=6.

Crossrefs

Programs

  • Magma
    [3*Binomial(10*n+6, n)/(5*n+3): n in [0..30]]; // Vincenzo Librandi, Dec 27 2013
  • Mathematica
    Table[3 Binomial[10 n + 6, n]/(5 n + 3), {n, 0, 30}] (* Vincenzo Librandi, Dec 27 2013 *)
  • PARI
    a(n) = 3*binomial(10*n+6,n)/(5*n+3);
    
  • PARI
    {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(5/3))^6+x*O(x^n)); polcoeff(B, n)}
    

Formula

G.f. satisfies: B(x) = {1 + x*B(x)^(p/r)}^r, where p=10, r=6.
Showing 1-10 of 12 results. Next