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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A006106 Gaussian binomial coefficient [ n,3 ] for q = 4.

Original entry on oeis.org

1, 85, 5797, 376805, 24208613, 1550842085, 99277752549, 6354157930725, 406672215935205, 26027119554103525, 1665737215212030181, 106607206793565997285, 6822861635108183247077, 436663151052043168024805, 27946441769812674154891493
Offset: 3

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Author

Keywords

References

  • J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.
  • I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

Programs

  • Magma
    r:=3; q:=4; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 07 2016
  • Mathematica
    Table[QBinomial[n, 3, 4], {n, 3, 20}] (* Vincenzo Librandi, Aug 07 2016 *)
  • Sage
    [gaussian_binomial(n,3,4) for n in range(3,15)] # Zerinvary Lajos, May 27 2009
    

Formula

G.f.: x^3/((1-x)*(1-4*x)*(1-16*x)*(1-64*x)). - Simon Plouffe in his 1992 dissertation
a(n) = Product_{i=1..3} (4^(n-i+1)-1)/(4^i-1), by definition. - Vincenzo Librandi, Aug 07 2016

A006111 Gaussian binomial coefficient [ n,2 ] for q=5.

Original entry on oeis.org

1, 31, 806, 20306, 508431, 12714681, 317886556, 7947261556, 198682027181, 4967053120931, 124176340230306, 3104408566792806, 77610214474995931, 1940255363400777181, 48506384092648824056, 1212659602354367574056, 30316490059049924214681
Offset: 2

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Author

Keywords

References

  • J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.
  • I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

Programs

  • Maple
    A006111:=-1/(z-1)/(25*z-1)/(5*z-1); # [Simon Plouffe in his 1992 dissertation with offset 0]
  • Mathematica
    Transpose[NestList[Flatten[{Last[#],30Last[#]- 125First[#]+1}]&, {1,31}, 20]] [[1]]  (* Harvey P. Dale, Mar 26 2011 *)
    LinearRecurrence[{31, -155, 125}, {1, 31, 806}, 10] (* T. D. Noe, Mar 26 2011 *)
  • Sage
    [gaussian_binomial(n,2,5) for n in range(2,16)] # Zerinvary Lajos, May 28 2009

Formula

G.f.: x^2/[(1-x)(1-5x)(1-25x)].
a(n) = 6*a(n-1) - 5*a(n-2) + 25^(n-2), n>=4. - Vincenzo Librandi, Mar 20 2011
a(n) = 30*a(n-1) - 125*a(n-2) + 1, n>=3. - Vincenzo Librandi, Mar 20 2011
a(n) = -5^(n-1)/16 + 25^n/480 + 1/96. - R. J. Mathar, Mar 21 2011

Extensions

More terms from Harvey P. Dale, Mar 26 2011

A006112 Gaussian binomial coefficient [ n,3 ] for q = 5.

Original entry on oeis.org

1, 156, 20306, 2558556, 320327931, 40053706056, 5007031143556, 625886840206056, 78236053707784181, 9779511680526143556, 1222439084242108174806, 152804888634672088643556, 19100611156944225555440431, 2387576396558283557830831056
Offset: 3

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Author

Keywords

References

  • J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.
  • I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

Programs

  • Magma
    r:=3; q:=5; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 07 2016
  • Maple
    A006112:=1/(z-1)/(125*z-1)/(25*z-1)/(5*z-1); # [conjectured by Simon Plouffe in his 1992 dissertation]
    seq((5^n-1)*(5^n-5)*(5^n-25)/1488000, n=3..30); # Robert Israel, Feb 01 2018
  • Mathematica
    Table[QBinomial[n, 3, 5], {n, 3, 20}] (* Vincenzo Librandi, Aug 07 2016 *)
  • Sage
    [gaussian_binomial(n,3,5) for n in range(3,14)] # Zerinvary Lajos, May 27 2009
    

Formula

G.f.: x^3/((1-x)*(1-5*x)*(1-25*x)*(1-125*x)). - Vincenzo Librandi, Aug 07 2016
a(n) = Product_{i=1..3} (5^(n-i+1)-1)/(5^i-1), by definition. - Vincenzo Librandi, Aug 07 2016
a(n) = (5^n-1)*(5^n-5)*(5^n-25)/1488000. - Robert Israel, Feb 01 2018

A022193 Gaussian binomial coefficients [n, 10] for q = 2.

Original entry on oeis.org

1, 2047, 2794155, 3269560515, 3571013994483, 3774561792168531, 3926442969043883795, 4052305562169692070035, 4165817792093527797314451, 4274137206973266943778085267, 4380990637147598617372537398675
Offset: 10

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Author

Keywords

References

  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier-North Holland, 1978, p. 698.

Crossrefs

Gaussian binomial coefficient [n, k] for q = 2: A000225 (k = 1), A006095 (k = 2), A006096 (k = 3), A006097 (k = 4), A006110 (k = 5), A022189 - A022195 (k = 6 thru 12).

Programs

  • Magma
    r:=10; q:=2; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 03 2016
    
  • Mathematica
    Table[QBinomial[n, 10, 2], {n, 10, 40}] (* Vincenzo Librandi, Aug 03 2016 *)
  • PARI
    r=10; q=2; for(n=r,30, print1(prod(j=1,r,(1-q^(n-j+1))/(1-q^j)), ", ")) \\ G. C. Greubel, May 30 2018
  • Sage
    [gaussian_binomial(n,10,2) for n in range(10,21)] # Zerinvary Lajos, May 25 2009
    

Formula

a(n) = Product_{i=1..10} (2^(n-i+1)-1)/(2^i-1), by definition. - Vincenzo Librandi, Aug 03 2016
G.f. assuming an offset of 0: exp( Sum_{n >= 1} b(11*n)/b(n)*x^n/n ) = 1 + 2047*x + 2794155*x^2 + ..., where b(n) = A000225(n) = 2^n - 1. - Peter Bala, Jul 03 2025

A022194 Gaussian binomial coefficients [n, 11] for q = 2.

Original entry on oeis.org

1, 4095, 11180715, 26167664835, 57162391576563, 120843139740969555, 251413193158549532435, 518946525150879134496915, 1066968301301093995246996371, 2189425218271613769209626653075, 4488323837657412597958687922896275
Offset: 11

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Author

Keywords

References

  • F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier-North Holland, 1978, p. 698.

Crossrefs

Gaussian binomial coefficient [n, k] for q = 2: A000225 (k = 1), A006095 (k = 2), A006096 (k = 3), A006097 (k = 4), A006110 (k = 5), A022189 - A022195 (k = 6 thru 12).

Programs

  • Magma
    r:=11; q:=2; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 03 2016
    
  • Mathematica
    QBinomial[Range[11,30],11,2] (* Harvey P. Dale, Oct 21 2014 *)
  • PARI
    r=11; q=2; for(n=r,30, print1(prod(j=1,r,(1-q^(n-j+1))/(1-q^j)), ", ")) \\ G. C. Greubel, May 30 2018
  • Sage
    [gaussian_binomial(n,11,2) for n in range(11,22)] # Zerinvary Lajos, May 25 2009
    

Formula

a(n) = Product_{i=1..11} (2^(n-i+1)-1)/(2^i-1), by definition. - Vincenzo Librandi, Aug 03 2016
G.f. assuming an offset of 0: exp( Sum_{n >= 1} b(12*n)/b(n)*x^n/n ) = 1 + 4095*x + 11180715*x^2 + ..., where b(n) = A000225(n) = 2^n - 1. - Peter Bala, Jul 03 2025

A109765 Expansion of x/((4*x-1)*(2*x-1)*(x+1)).

Original entry on oeis.org

0, 1, 5, 23, 97, 399, 1617, 6511, 26129, 104687, 419089, 1677039, 6709521, 26840815, 107368721, 429485807, 1717965073, 6871903983, 27487703313, 109950988015, 439804301585, 1759217905391, 7036873019665, 28147494874863
Offset: 0

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Author

Creighton Dement, Aug 13 2005

Keywords

Comments

In reference to the program code given, 1baseksumseq[C*D] = A001045 (Jacobsthal sequence, disregard signs).
Floretion Algebra Multiplication Program, FAMP Code: 1basejsumseq[C*D] with C = - 'j + 'k - j' + k' - 'ii' - 'ij' - 'ik' - 'ji' - 'ki' and D = + .5'i + .5'k - .5j' - .5k' + .5'ii' + .5'jj' + .5'jk' + .5'ki'; sumtype: sum[Y[15]] = sum[Y[ * ]], disregard signs

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[x/((4x-1)(2x-1)(x+1)),{x,0,30}],x] (* or *)
    LinearRecurrence[{5,-2,-8},{0,1,5},30] (* Harvey P. Dale, Jan 02 2013 *)

Formula

a(n) = 5*a(n-1) - 2*a(n-2) - 8*a(n-3), n >= 3.
a(n) = (1/15)*(6*4^n-5*2^n-(-1)^n).
a(n+1) + a(n) = A006516(n+1).
a(n+2) - a(n) = A010036(n+1).

A260638 Irregular table: list of symmetric n X n matrices made from 2-binomial coefficients, read by rows, where the k-th row of any n X n matrix is filled with binomial coefficients [k-1,k-1]..[k+n-2,k-1] (for q=2).

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 1, 1, 3, 7, 1, 7, 35, 1, 1, 1, 1, 1, 3, 7, 15, 1, 7, 35, 155, 1, 15, 155, 1395, 1, 1, 1, 1, 1, 1, 3, 7, 15, 31, 1, 7, 35, 155, 651, 1, 15, 155, 1395, 11811, 1, 31, 651, 11811, 200787, 1, 1, 1, 1, 1, 1, 1, 3, 7, 15, 31, 63, 1, 7, 35, 155
Offset: 1

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Author

Arkadiusz Wesolowski, Nov 11 2015

Keywords

Comments

The determinant of the n X n matrix is 2^((n/6)*(2*n^2 - 3*n + 1)), that is, A185995(n-1).
The permanent is in A260639.

Examples

			The irregular table starts:
1;
1, 1;
1, 3;
1, 1, 1;
1, 3, 7;
1, 7, 35;
		

Crossrefs

Programs

  • Mathematica
    Flatten@Flatten@Table[Table[QBinomial[r + c, r, 2], {r, 0, n}, {c, 0, n}], {n, 0, 5}]

A288853 Triangle read by rows: T(n,k) is the number of surjective linear mappings from an n-dimensional vector space over F_2 onto a k-dimensional vector space, n>=0, 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 1, 3, 6, 1, 7, 42, 168, 1, 15, 210, 2520, 20160, 1, 31, 930, 26040, 624960, 9999360, 1, 63, 3906, 234360, 13124160, 629959680, 20158709760, 1, 127, 16002, 1984248, 238109760, 26668293120, 2560156139520, 163849992929280, 1, 255, 64770, 16322040, 4047865920, 971487820800, 217613271859200, 41781748196966400, 5348063769211699200
Offset: 0

Views

Author

Geoffrey Critzer, Jun 18 2017

Keywords

Comments

The (q = 2) analog of A008279.
A022166(m,k)*T(n,k) is the number of m X n matrices over F_2 that have rank k.
a(n) is the number of n X n matrices over F_2 in Green's R class containing A where rank(A) = k. - Geoffrey Critzer, Oct 05 2022

Examples

			  1;
  1,  1;
  1,  3,   6;
  1,  7,  42,   168;
  1, 15, 210,  2520,  20160;
  1, 31, 930, 26040, 624960, 9999360;
  ...
		

Crossrefs

Columns k=0-10 give: A000012, A000225, 6*A006095, 168*A006096, 20160*A006097, 9999360*A006110, 20158709760*A022189, 163849992929280*A022190, 5348063769211699200*A022191, 699612310033197642547200*A022192, 366440137299948128422802227200*A022193.
Main diagonal gives A002884.
Cf. A022166.

Programs

  • Mathematica
    Table[Table[Product[q^n - q^i, {i, 0, k - 1}] /. q -> 2, {k, 0, n}], {n, 0,8}] // Grid

Formula

T(n,k) = Product_{j=0..k-1} (2^n - 2^j).
T(n,k) = A002884(k)*A022166(n,k).
Let g_m(x) = Sum_{n>=0} (2^m*x)^n/A005329(n) and e(x) = Sum_{n>=0} x^n/A005329(n). Then Sum_{k>=0} T(n,k)*x^k/A005329(k) = g_n(x)/e(x). - Geoffrey Critzer, Jun 01 2024

A346295 a(n) = Sum_{k=0..n} (2^k + 1) * (2^k + 2) / 2.

Original entry on oeis.org

3, 9, 24, 69, 222, 783, 2928, 11313, 44466, 176307, 702132, 2802357, 11197110, 44763831, 179006136, 715926201, 2863508154, 11453639355, 45813770940, 183253510845, 733010897598, 2932037298879, 11728136612544, 46912521284289, 187650034805442, 750600038558403
Offset: 0

Views

Author

Paul Weisenhorn, Jul 13 2021

Keywords

Comments

All terms are multiples of 3.

Crossrefs

Cf. A028401 (first differences).

Programs

  • Maple
    a:= proc(n) option remember:
    if n=0 then 3 else (2^n+1)*(2^n+2)/2+procname(n-1) fi:
    end proc:
    seq(a(n), n=0..30);
  • Mathematica
    Accumulate @ Table[(2^k + 1)*(2^k + 2)/2, {k, 0, 25}] (* Amiram Eldar, Jul 27 2021 *)
    LinearRecurrence[{8,-21,22,-8},{3,9,24,69},30] (* Harvey P. Dale, Nov 21 2021 *)
  • PARI
    a(n)=sum(k=0, n, (2^k+1)*(2^k+2)/2); \\ Michel Marcus, Jul 16 2021

Formula

a(n) = (2^(n+1) + 4) * (2^(n+1) + 5) / 6 - 4 + n.
More generally: let f(n, b) be the triangular sum Sum_{k=0..n} (2^k+b) * (2^k+b+1) / 2.
f(n, b) = (2^(n+1) + 3*b + 1) * (2^(n+1) + 3*b + 2) / 6 - (b + 1)^2 + b*(b + 1)*n / 2.
G.f.: ((b^2+3*b+2)/2 - (3*b^2+8*b+4)*x + (4*b^2+8*b+3)*x^2) / ((4*x-1) * (2*x-1) * (x-1)^2).
E.g.f.: exp(x) * ((6*b+3)*exp(x) + 2*exp(3*x) + 3(b^2+b)*x/2 + (3*b^2-3*b-4) / 2) / 3.
Then b = -1 gives A006095, b = 0 gives A076024, b = 1 gives A346295, b = 2 gives A346375.
G.f.: 3*(5*x^2 - 5*x + 1) / ((4*x - 1) * (2*x - 1) * (x - 1)^2).
a(n) = 8*a(n-1) - 21*a(n-2) + 22*a(n-3) - 8*a(n-4) for n > 3.
This recurrence is valid for all sequences f(n,b).
E.g.f.: exp(x) * (9*exp(x) + 2*exp(3*x) + 3*x - 2) / 3. - Stefano Spezia, Aug 13 2021

A346375 a(n) = Sum_{k=0..n} (2^k + 2) * (2^k + 3) / 2.

Original entry on oeis.org

6, 16, 37, 92, 263, 858, 3069, 11584, 44995, 177350, 704201, 2806476, 11205327, 44780242, 179038933, 715991768, 2863639259, 11453901534, 45814295265, 183254559460, 733012994791, 2932041493226, 11728145001197, 46912538061552, 187650068359923, 750600105667318, 3002400087124729
Offset: 0

Views

Author

Paul Weisenhorn, Jul 14 2021

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember:
         if n=0 then 6 else procname(n-1)+(2^n+3)*(2^n+2)/2 fi:
        end proc:
    seq(a(n), n=0..26);
  • Mathematica
    a[n_]:=Sum[(2^k+2)*(2^k+3)/2,{k,0,n}];Array[a,30,0] (* Giorgos Kalogeropoulos, Jul 27 2021 *)
  • PARI
    a(n) = sum(k=0, n, (2^k+2)*(2^k+3)/2); \\ Michel Marcus, Jul 28 2021

Formula

a(n) = Sum_{k=0..n} (2^k + 2) * (2^k + 3) / 2.
a(n) = (2^(n+1) + 7) * (2^(n+1) + 8)/6 - 9 + 3*n.
More generally: let f(n, b) = Sum_{k=0..n} (2^k + b) * (2^k + b + 1)/2 then f(n, b) = (2^(n+1) + 3*b + 1) * (2^(n+1) + 3*b + 2) / 6 - (b + 1)^2 + b*(b + 1)*n/2.
G.f.: ((b^2+3*b+2)/2 - (3*b^2+8*b+4)*x + (4*b^2+8*b+3)*x^2) / ((4*x-1) * (2*x-1) * (x-1)^2).
E.g.f.: exp(x)*((6*b+3)*exp(x) + 2*exp(3*x) + 3*(b^2+b)*x/2 +(3*b^2-3*b-4) / 2) / 3.
Then b = -1 gives A006095, b = 0 gives A076024, b = 1 gives A346295, b = 2 gives A346375.
a(n) = 8*a(n-1) - 21*a(n-2) + 22*a(n-3) - 8*a(n-4) with n > 3.
This recurrence is valid for all sequences f(n, b).
G.f.: (35*x^2 - 32*x + 6) / ((4*x - 1) * (2*x - 1) * (x - 1)^2).
E.g.f.: exp(x) * (1 + 15*exp(x) + 2*exp(3*x) + 9*x)/3. - Stefano Spezia, Aug 15 2021
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