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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A015083 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=2.

Original entry on oeis.org

1, 1, 3, 17, 171, 3113, 106419, 7035649, 915028347, 236101213721, 121358941877763, 124515003203007345, 255256125633703622475, 1046039978882750301409545, 8571252355254982356001107795, 140448544236464264647066322058465, 4602498820363674769217316088142020635
Offset: 0

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Author

Keywords

Comments

Limit_{n->inf} a(n)/2^((n-1)(n-2)/2) = Product{k>=1} 1/(1-1/2^k) = 3.462746619455... (cf. A065446). - Paul D. Hanna, Jan 24 2005
It appears that the Hankel transform is 2^A002412(n). - Paul Barry, Aug 01 2008
Hankel transform of aerated sequence is A125791. - Paul Barry, Dec 15 2010

Examples

			G.f. = 1 + x + 3*x^2 + 17*x^3 + 171*x^4 + 3113*x^5 + 106419*x^6 + 7035649*x^7 + ...
From _Seiichi Manyama_, Dec 05 2016: (Start)
a(1) = 1,
a(2) = 2^1 + 1 = 3,
a(3) = 2^3 + 2^2 + 2*2^1 + 1 = 17,
a(4) = 2^6 + 2^5 + 2*2^4 + 3*2^3 + 3*2^2 + 3*2^1 + 1 = 171. (End)
		

Crossrefs

Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), this sequence (q=2), A015084 (q=3), A015085 (q=4), A015086 (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=2 of A090182, A290759.

Programs

  • Mathematica
    a[n_] := a[n] = Sum[2^i*a[i]*a[n - i - 1], {i, 0, n - 1}];
    a[0] = 1; Array[a, 16, 0] (* Robert G. Wilson v, Dec 24 2016 *)
    m = 17; ContinuedFractionK[If[i == 1, 1, -2^(i-2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • PARI
    a(n)=if(n==0,1,sum(i=0,n-1,2^i*a(i)*a(n-1-i))) \\  Paul D. Hanna
    
  • PARI
    {a(n) = my(A); if( n<1, n==0, A = vector(n, i, 1); for(k=0, n-1, A[k+1] = if( k<1, 1, A[k]*(1+2^k) + sum(i=1, k-1, 2^i * A[i] * A[k-i]))); A[n])}; /* Michael Somos, Jan 30 2005 */
    
  • PARI
    {a(n) = my(A); if( n<0, 0, A = O(x); for(k=1, n, A = 1 / (1 - x * subst(A, x, 2*x))); polcoeff(A, n))}; /* Michael Somos, Jan 30 2005 */
    
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015083(n)
      A(2, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=2 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(2*x)) = 1/(1-x/(1-2*x/(1-2^2*x/(1-2^3*x/(1-...))))) (continued fraction). - Paul D. Hanna, Jan 24 2005
G.f. satisfies: A(x) = Sum_{n>=0} Product_{k=0..n-1} 2^k*x*A(2^k*x). - Paul D. Hanna, May 17 2010
a(n) = the upper left term in M^(n-1), M = the infinite square production matrix:
1, 2, 0, 0, 0, ...
1, 2, 4, 0, 0, ...
1, 2, 4, 8, 0, ...
1, 2, 4, 8, 16, ...
...
Also, a(n+1) = sum of top row terms of M^(n-1). Example: top row of M^3 = (17, 34, 56, 64, 0, 0, 0, ...); where a(4) = 17 and a(5) = 171 = (17 + 34 + 56 + 64). - Gary W. Adamson, Jul 14 2011
G.f.: T(0), where T(k) = 1 - x*(2^k)/(x*(2^k) - 1/T(k+1) ); (continued fraction). - Sergei N. Gladkovskii, Oct 17 2013

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 05 2016

A090181 Triangle of Narayana (A001263) with 0 <= k <= n, read by rows.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 6, 6, 1, 0, 1, 10, 20, 10, 1, 0, 1, 15, 50, 50, 15, 1, 0, 1, 21, 105, 175, 105, 21, 1, 0, 1, 28, 196, 490, 490, 196, 28, 1, 0, 1, 36, 336, 1176, 1764, 1176, 336, 36, 1, 0, 1, 45, 540, 2520, 5292, 5292, 2520, 540, 45, 1, 0, 1, 55, 825, 4950, 13860
Offset: 0

Views

Author

Philippe Deléham, Jan 19 2004

Keywords

Comments

Number of Dyck n-paths with exactly k peaks. - Peter Luschny, May 10 2014

Examples

			Triangle starts:
[0] 1;
[1] 0, 1;
[2] 0, 1,  1;
[3] 0, 1,  3,   1;
[4] 0, 1,  6,   6,    1;
[5] 0, 1, 10,  20,   10,    1;
[6] 0, 1, 15,  50,   50,   15,    1;
[7] 0, 1, 21, 105,  175,  105,   21,   1;
[8] 0, 1, 28, 196,  490,  490,  196,  28,  1;
[9] 0, 1, 36, 336, 1176, 1764, 1176, 336, 36, 1;
		

Crossrefs

Mirror image of triangle A131198. A000108 (row sums, Catalan).
Sum_{k=0..n} T(n,k)*x^k = A000007(n), A000108(n), A006318(n), A047891(n+1), A082298(n), A082301(n), A082302(n), A082305(n), A082366(n), A082367(n) for x=0,1,2,3,4,5,6,7,8,9. - Philippe Deléham, Aug 10 2006
Sum_{k=0..n} x^(n-k)*T(n,k) = A090192(n+1), A000012(n), A000108(n), A001003(n), A007564(n), A059231(n), A078009(n), A078018(n), A081178(n), A082147(n), A082181(n), A082148(n), A082173(n) for x = -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11. - Philippe Deléham, Oct 21 2006
Sum_{k=0..n} T(n,k)*x^k*(x-1)^(n-k) = A000012(n), A006318(n), A103210(n), A103211(n), A133305(n), A133306(n), A133307(n), A133308(n), A133309(n) for x = 1, 2, 3, 4, 5, 6, 7, 8, 9, respectively. - Philippe Deléham, Oct 20 2007

Programs

  • Magma
    [[(&+[(-1)^(j-k)*Binomial(2*n-j,j)*Binomial(j,k)*Binomial(2*n-2*j,n-j)/(n-j+1): j in [0..n]]): k in [0..n]]: n in [0..10]];
  • Maple
    A090181 := (n,k) -> binomial(n,n-k)*binomial(n-1,n-k)/(n-k+1):
    seq(print( seq(A090181(n,k),k=0..n)),n=0..5); # Peter Luschny, May 10 2014
    egf := 1+int((sqrt(t)*exp((1+t)*x)*BesselI(1,2*sqrt(t)*x))/x,x);
    s := n -> n!*coeff(series(egf,x,n+2),x,n);
    seq(print(seq(coeff(s(n),t,j),j=0..n)),n=0..9); # Peter Luschny, Oct 30 2014
    T := proc(n, k) option remember; if k = n or k = 1 then 1 elif k < 1 then 0 else (2*n/k - 1) * T(n-1, k-1) + T(n-1, k) fi end:
    for n from 0 to 8 do seq(T(n, k), k = 0..n) od;  # Peter Luschny, Dec 31 2024
  • Mathematica
    Flatten[Table[Sum[(-1)^(j-k) * Binomial[2n-j,j] * Binomial[j,k] * CatalanNumber[n-j], {j, 0, n}], {n,0,11},{k,0,n}]] (* Indranil Ghosh, Mar 05 2017 *)
    p[0, ] := 1; p[1, x] := x; p[n_, x_] := ((2 n - 1) (1 + x) p[n - 1, x] - (n - 2) (x - 1)^2 p[n - 2, x]) / (n + 1);
    Table[CoefficientList[p[n, x], x], {n, 0, 9}] // TableForm (* Peter Luschny, Apr 26 2022 *)
  • PARI
    c(n) = binomial(2*n,n)/ (n+1);
    tabl(nn) = {for(n=0, nn, for(k=0, n, print1(sum(j=0, n, (-1)^(j-k) * binomial(2*n-j,j) * binomial(j,k) * c(n-j)),", ");); print(););};
    tabl(11); \\ Indranil Ghosh, Mar 05 2017
    
  • Python
    from functools import cache
    @cache
    def Trow(n):
        if n == 0: return [1]
        if n == 1: return [0, 1]
        if n == 2: return [0, 1, 1]
        A = Trow(n - 2) + [0, 0]
        B = Trow(n - 1) + [1]
        for k in range(n - 1, 1, -1):
            B[k] = (((B[k] + B[k - 1]) * (2 * n - 1)
                   - (A[k] - 2 * A[k - 1] + A[k - 2]) * (n - 2)) // (n + 1))
        return B
    for n in range(10): print(Trow(n)) # Peter Luschny, May 02 2022
    
  • Sage
    def A090181_row(n):
        U = [0]*(n+1)
        for d in DyckWords(n):
            U[d.number_of_peaks()] +=1
        return U
    for n in range(8): A090181_row(n) # Peter Luschny, May 10 2014
    

Formula

Triangle T(n, k), read by rows, given by [0, 1, 0, 1, 0, 1, 0, 1, 0, 1, ...] DELTA [1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, ...] where DELTA is the operator defined in A084938. T(0, 0) = 1, T(n, 0) = 0 for n>0, T(n, k) = C(n-1, k-1)*C(n, k-1)/k for k>0.
Sum_{j>=0} T(n,j)*binomial(j,k) = A060693(n,k). - Philippe Deléham, May 04 2007
Sum_{k=0..n} T(n,k)*10^k = A143749(n+1). - Philippe Deléham, Oct 14 2008
From Paul Barry, Nov 10 2008: (Start)
Coefficient array of the polynomials P(n,x) = x^n*2F1(-n,-n+1;2;1/x).
T(n,k) = Sum_{j=0..n} (-1)^(j-k)*C(2n-j,j)*C(j,k)*A000108(n-j). (End)
Sum_{k=0..n} T(n,k)*5^k*3^(n-k) = A152601(n). - Philippe Deléham, Dec 10 2008
Sum_{k=0..n} T(n,k)*(-2)^k = A152681(n); Sum_{k=0..n} T(n,k)*(-1)^k = A105523(n). - Philippe Deléham, Feb 03 2009
Sum_{k=0..n} T(n,k)*2^(n+k) = A156017(n). - Philippe Deléham, Nov 27 2011
T(n, k) = C(n,n-k)*C(n-1,n-k)/(n-k+1). - Peter Luschny, May 10 2014
E.g.f.: 1+Integral((sqrt(t)*exp((1+t)*x)*BesselI(1,2*sqrt(t)*x))/x dx). - Peter Luschny, Oct 30 2014
G.f.: (1+x-x*y-sqrt((1-x*(1+y))^2-4*y*x^2))/(2*x). - Alois P. Heinz, Nov 28 2021, edited by Ron L.J. van den Burg, Dec 19 2021
T(n, k) = [x^k] (((2*n - 1)*(1 + x)*p(n-1, x) - (n - 2)*(x - 1)^2*p(n-2, x))/(n + 1)) with p(0, x) = 1 and p(1, x) = x. - Peter Luschny, Apr 26 2022
Recursion based on rows (see the Python program):
T(n, k) = (((B(k) + B(k-1))*(2*n - 1) - (A(k) - 2*A(k-1) + A(k-2))*(n-2))/(n+1)), where A(k) = T(n-2, k) and B(k) = T(n-1, k), for n >= 3. # Peter Luschny, May 02 2022

A015084 Carlitz-Riordan q-Catalan numbers for q=3.

Original entry on oeis.org

1, 1, 4, 43, 1252, 104098, 25511272, 18649337311, 40823535032644, 267924955577741566, 5274102955963545775864, 311441054994969341088610030, 55171471477692117486494217498280
Offset: 0

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Author

Keywords

Comments

Limit_{n->inf} a(n)/3^((n-1)(n-2)/2) = Product{k>=1} 1/(1-1/3^k) = 1.785312341998534190367486296013703535718796... - Paul D. Hanna, Jan 24 2005
It appears that the Hankel transform is 3^A002412(n). - Paul Barry, Aug 01 2008
Hankel transform of the aerated sequence is 3^C(n+1,3). - Paul Barry, Oct 31 2008

Examples

			G.f. = 1 + x + 4*x^2 + 43*x^3 + 1252*x^4 + 104098*x^5 + 25511272*x^6 + ...
From _Seiichi Manyama_, Dec 05 2016: (Start)
a(1) = 1,
a(2) = 3^1 + 1 = 4,
a(3) = 3^3 + 3^2 + 2*3^1 + 1 = 43,
a(4) = 3^6 + 3^5 + 2*3^4 + 3*3^3 + 3*3^2 + 3*3^1 + 1 = 1252. (End)
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), this sequence (q=3), A015085 (q=4), A015086 (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=3 of A090182, A290759.

Programs

  • Maple
    A015084 := proc(n)
        option remember;
        if n = 1 then
            1;
        else
        add(3^(i-1)*procname(i)*procname(n-i),i=1..n-1) ;
        end if;
    end proc: # R. J. Mathar, Sep 29 2012
  • Mathematica
    a[n_] := a[n] = Sum[3^i*a[i]*a[n -i -1], {i, 0, n -1}]; a[0] = 1; Array[a, 16, 0] (* Robert G. Wilson v, Dec 24 2016 *)
    m = 13; ContinuedFractionK[If[i == 1, 1, -3^(i-2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • PARI
    a(n)=if(n==1,1,sum(i=1,n-1,3^(i-1)*a(i)*a(n-i))) \\ Paul D. Hanna
    
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015084(n)
      A(3, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=3 and a(0)=1.
G.f. satisfies: A(x) = 1/(1-x*A(3*x)) = 1/(1-x/(1-3*x/(1-3^2*x/(1-3^3*x/(1-...))))) (continued fraction). - Paul D. Hanna, Jan 24 2005
a(n) = the upper left term in M^n, M an infinite production matrix as follows:
1, 3, 0, 0, 0, 0, ...
1, 3, 9, 0, 0, 0, ...
1, 3, 9, 27, 0, 0, ...
1, 3, 9, 27, 81, 0, ...
... - Gary W. Adamson, Jul 14 2011
G.f.: T(0), where T(k) = 1 - x*3^k/(x*3^k - 1/T(k+1) ); (continued fraction). - Sergei N. Gladkovskii, Oct 18 2013

Extensions

More terms from Paul D. Hanna, Jan 24 2005
Offset changed to 0 by Seiichi Manyama, Dec 05 2016

A015085 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=4.

Original entry on oeis.org

1, 1, 5, 89, 5885, 1518897, 1558435125, 6386478643785, 104648850228298925, 6858476391221411106209, 1797922152786660462507074405, 1885261615172756172119161342909753
Offset: 0

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Author

Keywords

Examples

			G.f. = 1 + x + 5*x^2 + 89*x^3 + 5885*x^4 + 1518897*x^5 + 1558435125*x^6 + ...
From _Seiichi Manyama_, Dec 05 2016: (Start)
a(1) = 1,
a(2) = 4^1 + 1 = 5,
a(3) = 4^3 + 4^2 + 2*4^1 + 1 = 89,
a(4) = 4^6 + 4^5 + 2*4^4 + 3*4^3 + 3*4^2 + 3*4^1 + 1 = 5885. (End)
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), this sequence (q=4), A015086 (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=4 of A090182, A290759.

Programs

  • Mathematica
    a[n_] := a[n] = Sum[4^i*a[i]*a[n -i -1], {i, 0, n -1}]; a[0] = 1; Array[a, 16, 0] (* Robert G. Wilson v, Dec 24 2016 *)
    m = 12; ContinuedFractionK[If[i == 1, 1, -4^(i - 2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015085(n)
      A(4, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=4 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(4*x)) = 1/(1-x/(1-4*x/(1-4^2*x/(1-4^3*x/(1-...))))) (continued fraction). - Seiichi Manyama, Dec 26 2016
a(n) ~ c * 2^(n*(n-1)), where c = Product{j>=1} 1/(1-1/4^j) = 1/QPochhammer(1/4) = 1.4523536424495970158347130224852748733612279788... - Vaclav Kotesovec, Nov 03 2021

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 05 2016

A015097 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=-2.

Original entry on oeis.org

1, 1, -1, -7, 47, 873, -26433, -1749159, 220526159, 56904690761, -29022490524961, -29777360924913095, 60924625361199230575, 249669263740090899509545, -2044791574538659983034398465, -33505955988983997787211823466215
Offset: 0

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Author

Keywords

Examples

			G.f. = 1 + x - x^2 - 7*x^3 + 47*x^4 + 873*x^5 + ...
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), this sequence (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), A015085 (q=4), A015086 (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=2 of A290789.

Programs

  • Mathematica
    m = 16;
    ContinuedFractionK[If[i == 1, 1, (-1)^(i+1) 2^(i-2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • Python
    l=[1]
    for n in range(1, 21):
        l.append(sum([(-2)**i*l[i]*l[n - 1 - i] for i in range(n)]))
    print(l) # Indranil Ghosh, Aug 14 2017
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015097(n)
      A(-2, n)
    end # Seiichi Manyama, Dec 24 2016
    

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=-2 and a(0)=1.
G.f: 1/(1-x/(1+2x/(1-4x/(1+8x/(1-16x/(1+... (continued fraction). - Paul Barry, Jan 15 2009
G.f. satisfies: A(x) = 1 / (1 - x*A(-2*x)). - Seiichi Manyama, Dec 27 2016

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 24 2016

A015098 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=-3.

Original entry on oeis.org

1, 1, -2, -23, 586, 48778, -11759396, -8596478231, 18783386191762, 123275424165263086, -2426183754235085042972, -143268577734839493464012630, 25379312219817753259837452498340
Offset: 0

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Author

Keywords

Examples

			G.f. = 1 + x - 2*x^2 - 23*x^3 + 586*x^4 + 48778*x^5 + ...
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), this sequence (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), A015085 (q=4), A015086 (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=3 of A290789.

Programs

  • Mathematica
    a[1] := 1; a[n_] := a[n] = Sum[(-3)^(i - 1)*a[i]*a[n - i], {i, 1, n - 1}]; Array[a, 20, 1] (* G. C. Greubel, Dec 24 2016 *)
    m = 13; ContinuedFractionK[If[i == 1, 1, (-1)^(i+1) 3^(i-2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015098(n)
      A(-3, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=-3 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(-3*x)) = 1/(1-x/(1+3*x/(1-3^2*x/(1+3^3*x/(1-...))))) (continued fraction). - Seiichi Manyama, Dec 27 2016

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 24 2016

A015099 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=-4.

Original entry on oeis.org

1, 1, -3, -55, 3429, 885137, -904638963, -3707218743911, 60731665539301365, 3980231929565571675617, -1043385959026442521712292579, -1094071562179856506263860787078039
Offset: 0

Views

Author

Keywords

Examples

			G.f. = 1 + x - 3*x^2 - 55*x^3 + 3429*x^4 + 885137*x^5 + ...
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), this sequence (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), A015085 (q=4), A015086 (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=4 of A290789.

Programs

  • Mathematica
    a[1] := 1; a[n_] := a[n] = Sum[(-4)^(i - 1)*a[i]*a[n - i], {i, 1, n - 1}]; Array[a, 20, 1] (* G. C. Greubel, Dec 24 2016 *)
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015099(n)
      A(-4, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=-4 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(-4*x)) = 1/(1-x/(1+4*x/(1-4^2*x/(1+4^3*x/(1-...))))) (continued fraction). - Seiichi Manyama, Dec 27 2016

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 24 2016

A015086 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=5.

Original entry on oeis.org

1, 1, 6, 161, 20466, 12833546, 40130703276, 627122621447281, 48995209411107768186, 19138851672289046707772366, 37380607950584029444762130426196, 365045074278810327614287737714877590426, 17824467247610520516685844671190387550839429556, 4351676609772600016156555731067955626656370700291086836
Offset: 0

Views

Author

Keywords

Examples

			G.f. = 1 + x + 6*x^2 + 161*x^3 + 20466*x^4 + 12833546*x^5 + 40130703276*x^6 + ...
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), A015085 (q=4), this sequence (q=5), A015089 (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=5 of A090182, A290759.

Programs

  • Mathematica
    a[n_] := a[n] = Sum[5^i*a[i]*a[n -i -1], {i, 0, n -1}];
    a[0] = 1; Array[a, 12, 0] (* Robert G. Wilson v, Dec 24 2016 *)
    m = 11; ContinuedFractionK[If[i == 1, 1, -5^(i - 2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015086(n)
      A(5, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=5 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(5*x)) = 1/(1-x/(1-5*x/(1-5^2*x/(1-5^3*x/(1-...))))) (continued fraction). - Seiichi Manyama, Dec 26 2016

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 24 2016

A015089 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=6.

Original entry on oeis.org

1, 1, 7, 265, 57799, 75025897, 583552122727, 27227375795690569, 7621977131953256556295, 12802009986716861649949951657, 129014790439200398432389878440405671
Offset: 0

Views

Author

Keywords

Examples

			G.f. = 1 + x + 7*x^2 + 265*x^3 + 57799*x^4 + 75025897*x^5 + 583552122727*x^6 + ...
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), A015085 (q=4), A015086 (q=5), this sequence (q=6), A015091 (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=6 of A090182, A290759.

Programs

  • Mathematica
    a[n_] := a[n] = Sum[6^i*a[i]*a[n -i -1], {i, 0, n -1}]; a[0] = 1; Array[a, 16, 0] (* Robert G. Wilson v, Dec 24 2016 *)
    m = 11; ContinuedFractionK[If[i == 1, 1, -6^(i - 2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015089(n)
      A(6, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=6 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(6*x)) = 1/(1-x/(1-6*x/(1-6^2*x/(1-6^3*x/(1-...))))) (continued fraction). - Seiichi Manyama, Dec 26 2016

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 24 2016

A015091 Carlitz-Riordan q-Catalan numbers (recurrence version) for q=7.

Original entry on oeis.org

1, 1, 8, 407, 140456, 337520898, 5673390747984, 667480099386451779, 549699898523248769128232, 3168911624115201777713785471406, 127877020635106970108300418456422667248
Offset: 0

Views

Author

Keywords

Examples

			G.f. = 1 + x + 8*x^2 + 407*x^3 + 140456*x^4 + 337520898*x^5 + ...
		

Crossrefs

Cf. A227543.
Cf. A015108 (q=-11), A015107 (q=-10), A015106 (q=-9), A015105 (q=-8), A015103 (q=-7), A015102 (q=-6), A015100 (q=-5), A015099 (q=-4), A015098 (q=-3), A015097 (q=-2), A090192 (q=-1), A000108 (q=1), A015083 (q=2), A015084 (q=3), A015085 (q=4), A015086 (q=5), A015089 (q=6), this sequence (q=7), A015092 (q=8), A015093 (q=9), A015095 (q=10), A015096 (q=11).
Column k=7 of A090182, A290759.

Programs

  • Mathematica
    a[n_] := a[n] = Sum[7^i*a[i]*a[n -i -1], {i, 0, n -1}]; a[0] = 1; Array[a, 16, 0] (* Robert G. Wilson v, Dec 24 2016 *)
    m = 11; ContinuedFractionK[If[i == 1, 1, -7^(i - 2) x], 1, {i, 1, m}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 17 2019 *)
  • Ruby
    def A(q, n)
      ary = [1]
      (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + q ** j * ary[j] * ary[i - 1 - j]}}
      ary
    end
    def A015091(n)
      A(7, n)
    end # Seiichi Manyama, Dec 24 2016

Formula

a(n+1) = Sum_{i=0..n} q^i*a(i)*a(n-i) with q=7 and a(0)=1.
G.f. satisfies: A(x) = 1 / (1 - x*A(7*x)) = 1/(1-x/(1-7*x/(1-7^2*x/(1-7^3*x/(1-...))))) (continued fraction). - Seiichi Manyama, Dec 26 2016

Extensions

Offset changed to 0 by Seiichi Manyama, Dec 24 2016
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