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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A024166 a(n) = Sum_{1 <= i < j <= n} (j-i)^3.

Original entry on oeis.org

0, 1, 10, 46, 146, 371, 812, 1596, 2892, 4917, 7942, 12298, 18382, 26663, 37688, 52088, 70584, 93993, 123234, 159334, 203434, 256795, 320804, 396980, 486980, 592605, 715806, 858690, 1023526, 1212751, 1428976, 1674992, 1953776, 2268497, 2622522, 3019422
Offset: 0

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Author

Keywords

Comments

Convolution of the cubes (A000578) with the positive integers a(n)=n+1, where all sequences have offset zero. - Graeme McRae, Jun 06 2006
a(n) gives the n-th antidiagonal sum of the convolution array A212891. - Clark Kimberling, Jun 16 2012
In general, the r-th successive summation of the cubes from 1 to n is (6*n^2 + 6*n*r + r^2 - r)*(n+r)!/((r+3)!*(n-1)!), n>0. Here r = 2. - Gary Detlefs, Mar 01 2013
The inverse binomial transform is (essentially) row n=2 of A087127. - R. J. Mathar, Aug 31 2022

Examples

			4*a(7) = 6384 = (0*1)^2 + (1*2)^2 + (2*3)^2 + (3*4)^2 + (4*5)^2 + (5*6)^2 + (6*7)^2 + (7*8)^2. - _Bruno Berselli_, Feb 05 2014
		

References

  • Elisabeth Busser and Gilles Cohen, Neuro-Logies - "Chercher, jouer, trouver", La Recherche, April 1999, No. 319, page 97.

Crossrefs

Programs

  • Haskell
    a024166 n = sum $ zipWith (*) [n+1,n..0] a000578_list
    -- Reinhard Zumkeller, Oct 14 2001
    
  • Magma
    [n*(n+1)*(n+2)*(3*n^2 + 6*n + 1)/60: n in [0..30]]; // G. C. Greubel, Nov 21 2017
    
  • Maple
    A024166:=n->n*(n+1)*(n+2)*(3*n^2 + 6*n + 1)/60: seq(A024166(n), n=0..50); # Wesley Ivan Hurt, Nov 21 2017
  • Mathematica
    Nest[Accumulate,Range[0,40]^3,2] (* Harvey P. Dale, Jan 10 2016 *)
    Table[n*(n+1)*(n+2)*(3*n^2 + 6*n + 1)/60, {n,0,30}] (* G. C. Greubel, Nov 21 2017 *)
  • PARI
    a(n)=sum(j=1,n, sum(m=1, j, sum(i=m*(m+1)/2-m+1, m*(m+1)/2, (2*i-1)))) \\ Alexander R. Povolotsky, May 17 2008
    
  • PARI
    for(n=0,30, print1(n*(n+1)*(n+2)*(3*n^2 + 6*n + 1)/60, ", ")) \\ G. C. Greubel, Nov 21 2017

Formula

From Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Dec 29 1999: (Start)
a(n) = Sum_{i=0..n} A000537(i), partial sums of A000537.
a(n) = n*(n+1)*(n+2)*(3*n^2 + 6*n + 1)/60. (End)
a(A004772(n)) mod 2 = 0; a(A016813(n)) mod 2 = 1. - Reinhard Zumkeller, Oct 14 2001
a(n) = Sum_{k=0..n} k^3*(n+1-k). - Paul Barry, Sep 14 2003; edited by Jon E. Schoenfield, Dec 29 2014
a(n) = 2*n*(n+1)*(n+2)*((n+1)^2 + 2*n*(n+2))/5!. This sequence could be obtained from the general formula a(n) = n*(n+1)*(n+2)*(n+3)* ...* (n+k) *(n*(n+k) + (k-1)*k/6)/((k+3)!/6) at k=2. - Alexander R. Povolotsky, May 17 2008
O.g.f.: x*(1 + 4*x + x^2)/(-1 + x)^6. - R. J. Mathar, Jun 06 2008
a(n) = (6*n^2 + 12*n + 2)*(n+2)!/(120*(n-1)!), n > 0. - Gary Detlefs, Mar 01 2013
a(n) = A222716(n+1)/10 = A000292(n)*A100536(n+1)/10. - Jonathan Sondow, Mar 04 2013
4*a(n) = Sum_{i=0..n} A000290(i)*A000290(i+1). - Bruno Berselli, Feb 05 2014
a(n) = Sum_{i=1..n} Sum_{j=1..n} i*j*(n - max(i, j) + 1). - Melvin Peralta, May 12 2016
a(n) = n*binomial(n+3, 4) + binomial(n+2, 5). - Tony Foster III, Nov 14 2017
a(n) = Sum_{i=1..n} i*A143037(n,n-i+1). - J. M. Bergot, Aug 30 2022

A087127 This table shows the coefficients of combinatorial formulas needed for generating the sequential sums of p-th powers of triangular numbers. The p-th row (p>=1) contains a(i,p) for i=1 to 2*p-1, where a(i,p) satisfies Sum_{i=1..n} C(i+1,2)^p = 3 * C(n+2,3) * Sum_{i=1..2*p-1} a(i,p) * C(n-1,i-1)/(i+2).

Original entry on oeis.org

1, 1, 2, 1, 1, 8, 19, 18, 6, 1, 26, 163, 432, 564, 360, 90, 1, 80, 1135, 6354, 18078, 28800, 26100, 12600, 2520, 1, 242, 7291, 77400, 405060, 1210680, 2211570, 2520000, 1751400, 680400, 113400, 1, 728, 45199, 862218, 7667646, 38350080, 118848420
Offset: 1

Views

Author

André F. Labossière, Aug 11 2003

Keywords

Comments

From Peter Bala, Mar 08 2018: (Start)
The table entries T(n,k) are the coefficients when expressing the polynomial C(x+2,2)^p of degree 2*p in terms of falling factorials: C(x+2,2)^p = Sum_{k = 0..2*p} T(p,k)*C(x,k). It follows that Sum_{i = 0..n-1} C(i+2,2)^p = Sum_{k = 0..2*p} T(p,k)*C(n,k+1).
The sum of the p-th powers of the triangular numbers is also given by Sum_{i = 0..n-1} C(i+2,2)^p = Sum_{k = 2..2*p} A122193(p,k)*C(n+2,k+1) for p >= 1. (End)

Examples

			Row 3 contains 1,8,19,18,6, so Sum_{i=1..n} C(i+1,2)^3 = (n+2) * C(n+1,2) * [ a(1,3)/3 + a(2,3)*C(n-1,1)/4 + a(3,3)*C(n-1,2)/5 + a(4,3)*C(n-1,3)/6 + a(5,3)*C(n-1,4)/7 ] = [ (n+2)*(n+1)*n/2 ] * [ 1/3 + (8/4)*C(n-1,1) + (19/5)*C(n-1,2) + (18/6)*C(n-1,3) + (6/7)*C(n-1,4). Cf. A085438 for more details.
From _Peter Bala_, Mar 08 2018: (Start)
Table begins
n=0 |1
n=1 |1   2     1
n=2 |1   8    19    18      6
n=3 |1  26   163   432    564    360     90
n=4 |1  80  1135  6354  18078  28800  26100  12600  2520
...
Row 2: C(i+2,2)^2 = C(i,0) + 8*C(i,1) + 19*C(i,2) + 18*C(i,3) + 6*C(i,4). Hence, Sum_{i = 0..n-1} C(i+2,2)^2 =  C(n,1) + 8*C(n,2) + 19*C(n,3) + 18*C(n,4) + 6*C(n,5). (End)
		

Crossrefs

Programs

  • GAP
    Flat(List([0..6],n->List([0..2*n],k->Sum([0..k],i->(-1)^(k-i)*Binomial(k,i)*Binomial(i+2,2)^n)))); # Muniru A Asiru, Mar 22 2018
  • Maple
    seq(seq(add( (-1)^(k-i)*binomial(k,i)*binomial(i+2,2)^n, i = 0..k), k = 0..2*n), n = 0..8); # Peter Bala, Mar 08 2018
  • Mathematica
    a[i_, p_] := Sum[Binomial[i - 1, 2*k - 2]*Binomial[i - 2*k + 3, i - 2*k + 1]^(p - 1) - Binomial[i - 1, 2*k - 1]*Binomial[i - 2*k + 2, i - 2*k]^(p - 1), {k, 1, (2*i + 1 + (-1)^(i - 1))/4}]; Table[If[p == 1, 1, a[i, p]], {p, 1, 10}, {i, 1, 2*p - 1}]//Flatten (* G. C. Greubel, Nov 23 2017 *)
    a[i_,p_]:=(-1)^i HypergeometricPFQ[ConstantArray[3,p]~Join~{2-i},ConstantArray[1,p],1];Table[a[i,p],{p,0,10},{i,2,2 p+2}]//Flatten (* Jonathan Burns, Mar 20 2018 *)
  • PARI
    {a(i, p) = sum(k=1, (2*i + 1 + (-1)^(i - 1))/4, binomial(i - 1, 2*k - 2)*binomial(i - 2*k + 3, i - 2*k + 1)^(p - 1) - binomial(i - 1, 2*k - 1)*binomial(i - 2*k + 2, i - 2*k)^(p - 1))}; for(p=1,8, for(i=1, 2*p-1, print1(if(p==1,1,a(i,p)), ", "))) \\ G. C. Greubel, Nov 23 2017
    

Formula

a(1, p) = 1, a(2, p) = 3^(p-1)-1, a(3, p) = 3^(p-1)*[2^(p-1)-2]+1, ..., a(2*p-3, p) = [ (6*p^4-20*p^3+21*p^2-7*p)*(2*p-4)! ]/[3*2^(p-1)], a(2*p-2, p) = [ (p^2-p)*(2*p-3)! ]/2^(p-2), a(2*p-1, p) = [ (p-1)*(2*p-3)! ]/2^(p-2).
a(i, p) = Sum_{k=1..[2*i+1+(-1)^(i-1)]/4} [ C(i-1, 2*k-2)*C(i-2*k+3, i-2*k+1)^(p-1) -C(i-1, 2*k-1)*C(i-2*k+2, i-2*k)^(p-1) ]
From Peter Bala, Mar 08 2018: (Start)
The following remarks assume row and column indices start at 0.
T(n,k) = Sum_{i = 0..k} (-1)^(k-i)*C(k,i)*C(i+2,2)^n. Equivalently, let v_n denote the sequence (1, 3^n, 6^n, 10^n, ...) regarded as an infinite column vector, where 1, 3, 6, 10, ... is the sequence of triangular numbers A000217. Then the n-th row of this table is determined by the matrix product P^(-1)*v_n, where P denotes Pascal's triangle A007318. Cf. A122193.
T(n+1,k) = C(k+2,2)*T(n,k) + 2*C(k+1,2)*T(n,k-1) + C(k,2)*T(n,k-2), with boundary conditions T(n,0) = 1 for all n and T(n,k) = 0 for k > 2*n.
Let R(n,x) denote the n-th row polynomial.
R(n+1,x) = 1/2!*(1 + x)^2*(d/dx)^2 (x^2*R(n,x)).
R(n,x) = Sum_{i >= 0} binomial(i+2,2)^n*x^i/(1 + x)^(i+1).
R(n,x) = (1 + x)^2 o (1 + x)^2 o ... o (1 + x)^2 (n factors), where o denotes the black diamond product of power series defined in Dukes and White. Note the polynomial x^2 o ... o x^2 (n factors) is the n-th row polynomial of A122193.
x^2*R(n,x) = (1 + x)^2 * the n-th row polynomial of A122193 (End)

Extensions

Edited by Dean Hickerson, Aug 16 2003

A086020 a(n) = Sum_(i=1..n) binomial(i+2,3)^2 [ Sequential sums of the tetragonal numbers or "tetras" (pyramidal, square) raised to power 2 (drawn from the 4th diagonal - left or right - of Pascal's Triangle) ].

Original entry on oeis.org

1, 17, 117, 517, 1742, 4878, 11934, 26334, 53559, 101959, 183755, 316251, 523276, 836876, 1299276, 1965132, 2904093, 4203693, 5972593, 8344193, 11480634, 15577210, 20867210, 27627210, 36182835, 46915011, 60266727, 76750327
Offset: 1

Views

Author

André F. Labossière, Jul 17 2003

Keywords

Comments

Kekulé numbers for certain benzenoids (see the Cyvin-Gutman reference, p. 243; expression in (13.26) yields same sequence with offset 0). - Emeric Deutsch, Aug 02 2005
Partial sums of A001249. - R. J. Mathar, Aug 19 2008

Examples

			a(8) = Sum_{i=1..8} binomial(i+2,3)^2 = (20*(8^7) + 210*(8^6) + 854*(8^5) + 1680*(8^4) + 1610*(8^3) + 630*(8^2) + 36*8)/7! = 26334.
		

Crossrefs

Programs

  • Magma
    [n*(n+1)*(n+2)*(n+3)*(2*n+3)*(5*n^2+15*n+1)/2520: n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Maple
    a:=n->n*(n+1)*(n+2)*(n+3)*(2*n+3)*(5*n^2+15*n+1)/2520: seq(a(n),n=1..31); # Emeric Deutsch
  • Mathematica
    Accumulate[Binomial[Range[30]+2,3]^2]  (* Harvey P. Dale, Mar 24 2011 *)
    LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{1,17,117,517,1742,4878, 11934, 26334},30] (* Harvey P. Dale, Aug 17 2014 *)
  • PARI
    a(n)=n*(n+1)*(n+2)*(n+3)*(2*n+3)*(5*n^2+15*n+1)/2520 \\ Charles R Greathouse IV, May 18 2015
    

Formula

a(n) = Sum_(i=1..n) binomial(i+2, 3)^2.
a(n) = ( C(n+3, 4)/35 )*( 35 + 84*C(n-1, 1) + 70*C(n-1, 2) + 20*C(n-1, 3) ).
a(n) = n*(n+1)*(n+2)*(n+3)*(2*n+3)(5*n^2 + 15*n + 1)/2520. - Emeric Deutsch, Aug 02 2005
O.g.f: x*(1+x)*(1 + 8*x + x^2)/(1-x)^8. - R. J. Mathar, Aug 19 2008

A085442 a(n) = Sum_{i=1..n} binomial(i+1,2)^7.

Original entry on oeis.org

1, 2188, 282124, 10282124, 181141499, 1982230040, 15475158552, 93839322648, 467508775773, 1989944010148, 7445104711204, 25010673566116, 76686775501847, 217396817767472, 575714897767472, 1436257466526768, 3398894618986905, 7674255436599996, 16612972826599996
Offset: 1

Views

Author

André F. Labossière, Jul 07 2003

Keywords

Crossrefs

Programs

  • Magma
    [(1/823680) *n*(n+1)*(n+2)*(429*n^12 +5148*n^11 +24123*n^10 +52470*n^9 +43047*n^8 -8856*n^7 +4109*n^6 +50430*n^5 -18796*n^4 -44472*n^3 +26864*n^2 +8352*n -5568): n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Mathematica
    Table[Sum[Binomial[k+1,2]^7, {k,1,n}], {n,1,30}] (* G. C. Greubel, Nov 22 2017 *)
    LinearRecurrence[{16,-120,560,-1820,4368,-8008,11440,-12870,11440,-8008,4368,-1820,560,-120,16,-1},{1,2188,282124,10282124,181141499,1982230040,15475158552,93839322648,467508775773,1989944010148,7445104711204,25010673566116,76686775501847,217396817767472,575714897767472,1436257466526768},20] (* Harvey P. Dale, May 11 2022 *)
  • PARI
    for(n=1,30, print1(sum(k=1,n, binomial(k+1,2)^7), ", ")) \\ G. C. Greubel, Nov 22 2017
    

Formula

a(n) = (1/823680) *n*(n+1)*(n+2)*(429*n^12 +5148*n^11 +24123*n^10 +52470*n^9 +43047*n^8 -8856*n^7 +4109*n^6 +50430*n^5 -18796*n^4 -44472*n^3 +26864*n^2 +8352*n -5568). - Vladeta Jovovic, Jul 07 2003
G.f.: x*(x^12 +2172*x^11 +247236*x^10 +6030140*x^9 +49258935*x^8 +163809288*x^7 +242384856*x^6 +163809288*x^5 +49258935*x^4 +6030140*x^3 +247236*x^2 +2172*x+ 1) / (x -1)^16. - Colin Barker, May 02 2014

A086030 a(n) = Sum_{i=1..n} C(i+6,7)^3.

Original entry on oeis.org

1, 513, 47169, 1775169, 37712169, 534505257, 5587534953, 46011772521, 312480135396, 1809674119396, 9165388162788, 41395684407012, 169328324418084, 635173167426084, 2207399512578084, 7167715400927268, 21902130296812161, 63361228916945025, 174437774859945025
Offset: 1

Views

Author

André F. Labossière, Jul 11 2003

Keywords

Examples

			a(3) = Sum_{i=1..3} C(6+i,7)^3 = C(10,8)*(5*C(16,14) + 210*C(15,14) + 1491*C(14,14))/5 = 47169.
		

Crossrefs

Programs

  • Magma
    [(1/28165294080000)*n^2*(1 + n)^2*(2 + n)^2*(3 + n)^2*(4 + n)^2*(5 + n)^2*(6 + n)^2*(7 + n)^2*(-3 + 3234*n + 6979*n^2 + 5292*n^3 + 1603*n^4 + 210*n^5 + 10*n^6): n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Maple
    A086030:=n->add(binomial(i+6,7)^3, i=1..n); seq(A086030(n), n=1..30); # Wesley Ivan Hurt, Dec 22 2013
  • Mathematica
    Table[Sum[Binomial[i + 6, 7]^3, {i, n}], {n, 30}] (* Wesley Ivan Hurt, Dec 22 2013 *)
  • PARI
    a(n) = sum(i=1, n, binomial(i+6, 7)^3); \\ Michel Marcus, Dec 22 2013
    

Formula

a(n) = C(n+7,8)*(5*C(n+13,14) + 210*C(n+12,14) + 1491*C(n+11,14) + 2828*C(n+10,14) + 1491*C(n+9,14) + 210*C(n+8,14) + 5*C(n+7,14))/5. - Yahia Kahloune, Dec 22 2013
-(n-1)^3*a(n) +(2*n+5)*(n^2+5*n+43)*a(n-1) -(n+6)^3*a(n-2)=0. - R. J. Mathar, Dec 22 2013
G.f.: -x*(x^14 + 490*x^13 + 35623*x^12 + 818300*x^11 + 7917371*x^10 + 37215794*x^9 + 91789005*x^8 + 123519792*x^7 + 91789005*x^6 + 37215794*x^5 + 7917371*x^4 + 818300*x^3 + 35623*x^2 + 490*x + 1)/(x-1)^23. - Vaclav Kotesovec, Dec 23 2013
a(n) = (1/28165294080000)*n^2*(1 + n)^2*(2 + n)^2*(3 + n)^2*(4 + n)^2*(5 + n)^2*(6 + n)^2*(7 + n)^2*(-3 + 3234*n + 6979*n^2 + 5292*n^3 + 1603*n^4 + 210*n^5 + 10*n^6). - G. C. Greubel, Nov 22 2017

A086023 a(n) = Sum_{i=1..n} C(i+3,4)^2.

Original entry on oeis.org

1, 26, 251, 1476, 6376, 22252, 66352, 175252, 420277, 931502, 1933503, 3796728, 7109128, 12773528, 22137128, 37160504, 60634529, 96454754, 149963979, 228375004, 341286880, 501309380, 724811880, 1032814380, 1452040005, 2016150006, 2767184031, 3757230256
Offset: 1

Views

Author

André F. Labossière, Jul 11 2003

Keywords

Crossrefs

Programs

  • Magma
    [n*(n+1)*(n+2)*(n+3)*(n+4)*(35*n^4 +280*n^3 +685*n^2 +500*n +12 )/181440: n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Mathematica
    Table[n*(n + 1)*(n + 2)*(n + 3)*(n + 4)*(35*n^4 + 280*n^3 + 685*n^2 + 500*n + 12)/181440, {n, 1, 50}] (* G. C. Greubel, Nov 22 2017 *)
    Accumulate[Binomial[Range[30]+3,4]^2] (* or *) LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{1,26,251,1476,6376,22252,66352,175252,420277,931502},30] (* Harvey P. Dale, May 06 2018 *)
  • PARI
    a(n) = sum(i=1, n, binomial(i+3, 4)^2); \\ Michel Marcus, Sep 05 2013
    
  • PARI
    Vec(x*(x^4+16*x^3+36*x^2+16*x+1)/(x-1)^10 + O(x^100)) \\ Colin Barker, May 02 2014
    

Formula

a(n) = ( C(n+4,5)/126 )*( 126 +420*C(n-1,1) +540*C(n-1,2) +315*C(n-1,3) +70*C(n-1,4) ).
a(n) = n*(n+1)*(n+2)*(n+3)*(n+4)*(35*n^4 +280*n^3 +685*n^2 +500*n +12 )/181440. - Bruno Berselli, Sep 05 2013
G.f.: x*(x^4+16*x^3+36*x^2+16*x+1) / (x-1)^10. - Colin Barker, May 02 2014

Extensions

More terms from Michel Marcus, Sep 05 2013

A086025 a(n) = Sum_{i=1..n} C(i+4,5)^2.

Original entry on oeis.org

1, 37, 478, 3614, 19490, 82994, 296438, 923702, 2580071, 6588075, 15606084, 34685508, 72976852, 146387476, 281597860, 521971876, 936053677, 1629533233, 2761788434, 4568378450, 7391175350, 11718183750, 18235516650, 27894475050, 41997225075, 62305185111
Offset: 1

Views

Author

André F. Labossière, Jul 11 2003

Keywords

Crossrefs

Programs

  • Magma
    [n*(2*n+5)*(n+5)*(n+4)*(n+3)*(n+2)*(n+1)*(63*n^4 +630*n^3 +1855*n^2 +1400*n +12)/19958400: n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Mathematica
    Table[n*(2*n+5)*(n+5)*(n+4)*(n+3)*(n+2)*(n+1)*(63*n^4 +630*n^3 +1855*n^2 +1400*n +12)/19958400, {n,1,30}] (* G. C. Greubel, Nov 22 2017 *)
    LinearRecurrence[{12,-66,220,-495,792,-924,792,-495,220,-66,12,-1},{1,37,478,3614,19490,82994,296438,923702,2580071,6588075,15606084,34685508},30] (* Harvey P. Dale, Dec 22 2024 *)
  • PARI
    for(n=1,30, print1(sum(i=1,n, binomial(i+4,5)^2), ", ")) \\ G. C. Greubel, Nov 22 2017
    

Formula

From R. J. Mathar, Jun 16 2010: (Start)
G.f.: x*(1+x)*(x^4+24*x^3+76*x^2+24*x+1)/(x-1)^12.
a(n) = n*(2*n+5)*(n+5)*(n+4)*(n+3)*(n+2)*(n+1)*(63*n^4 +630*n^3 +1855*n^2 +1400*n +12) / 19958400. (End)

Extensions

More terms from R. J. Mathar, Jun 16 2010

A086024 a(n) = Sum_{i=1..n} C(i+3,4)^3.

Original entry on oeis.org

1, 126, 3501, 46376, 389376, 2389752, 11650752, 47587752, 168875127, 534401002, 1537404003, 4080706128, 10109274128, 23590546128, 52243162128, 110473767504, 224205418629, 438589465254, 830009446129, 1524339072504, 2724140666880, 4748425291880, 8089787666880
Offset: 1

Views

Author

André F. Labossière, Jul 11 2003

Keywords

Crossrefs

Programs

  • Magma
    [(n/69189120)*(13824 + 960960*n^2 + 5885880*n^3 + 14370356*n^4 + 19269250*n^5 + 15996695*n^6 + 8678670*n^7 + 3138135*n^8 + 750750*n^9 + 114205*n^10 + 10010*n^11 + 385*n^12): n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Mathematica
    Table[(n/69189120)*(13824 + 960960*n^2 + 5885880*n^3 + 14370356*n^4 + 19269250*n^5 + 15996695*n^6 + 8678670*n^7 + 3138135*n^8 + 750750*n^9 + 114205*n^10 + 10010*n^11 + 385*n^12), {n,1,30}] (* G. C. Greubel, Nov 22 2017 *)
    LinearRecurrence[{14,-91,364,-1001,2002,-3003,3432,-3003,2002,-1001,364,-91,14,-1},{1,126,3501,46376,389376,2389752,11650752,47587752,168875127,534401002,1537404003,4080706128,10109274128,23590546128},30] (* Harvey P. Dale, Feb 18 2024 *)
  • PARI
    for(n=1,30, print1(sum(k=1,n, binomial(k+3, 4)^3), ", ")) \\ G. C. Greubel, Nov 22 2017
    

Formula

a(n) = ( C(n+4, 5)/1001 )*( 1001 +20020*C(n-1, 1) +125840*C(n-1, 2) +390390*C(n-1, 3) +695695*C(n-1, 4) +750750*C(n-1, 5) +486850*C(n-1, 6) +175175*C(n-1, 7) +26950*C(n-1, 8) ).
G.f.: x*(1 +112*x +1828*x^2 +8464*x^3 +13840*x^4 +8464*x^5 +1828*x^6 +112*x^7 +x^8)/(x-1)^14 . - R. J. Mathar, Dec 22 2013
-(n-1)^3*a(n) +2*(n+1)*(n^2+2*n+13)*a(n-1) -(n+3)^3*a(n-2)=0. - R. J. Mathar, Dec 22 2013
a(n) = (n/69189120)*(13824 + 960960*n^2 + 5885880*n^3 + 14370356*n^4 + 19269250*n^5 + 15996695*n^6 + 8678670*n^7 + 3138135*n^8 + 750750*n^9 + 114205*n^10 + 10010*n^11 + 385*n^12). - G. C. Greubel, Nov 22 2017

A086029 a(n) = Sum_{i=1..n} C(i+6,7)^2.

Original entry on oeis.org

1, 65, 1361, 15761, 124661, 751925, 3696581, 15475205, 56884430, 187758030, 565982734, 1578749710, 4117700254, 10127050654, 23648089054, 52733344990, 112835299639, 232623278455, 463695768455, 896396608455, 1684993889355, 3086944610955, 5522978819355
Offset: 1

Views

Author

André F. Labossière, Jul 11 2003

Keywords

Examples

			a(3) = C(10,8)*(-1*C(10,0) + 8*C(10,1) - 36*C(10,2) + 120*C(10,3) - 330*C(10,4) + 792*C(10,5) - 1716*C(10,6) + 3432*C(10,7))/6435 = 1361.
		

Crossrefs

Programs

  • Magma
    [(1/108972864000)*n*(1 + n)*(2 + n)*(3 + n)*(4 + n)*(5 + n)*(6 + n)*(7+n)*(7 + 2*n)*(60 + 64974*n + 126245*n^2 + 82467*n^3 + 23408*n^4 + 3003*n^5 + 143*n^6): n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Maple
    A086029:=n->add(binomial(i+6, 7)^2, i=1..n); seq(A086029(n), n=1..30); # Wesley Ivan Hurt, Dec 22 2013
  • Mathematica
    Table[Sum[Binomial[i + 6, 7]^2, {i, n}], {n, 30}] (* Wesley Ivan Hurt, Dec 22 2013 *)
    LinearRecurrence[{16,-120,560,-1820,4368,-8008,11440,-12870,11440,-8008,4368,-1820,560,-120,16,-1},{1,65,1361,15761,124661,751925, 3696581, 15475205, 56884430,187758030,565982734,1578749710,4117700254, 10127050654,23648089054,52733344990},40] (* Harvey P. Dale, Apr 25 2016 *)
  • PARI
    a(n) = sum(i=1, n, binomial(i+6, 7)^2); \\ Michel Marcus, Dec 22 2013
    
  • PARI
    Vec(x*(x+1)*(x^6+48*x^5+393*x^4+832*x^3+393*x^2+48*x+1)/(x-1)^16 + O(x^100)) \\ Colin Barker, May 02 2014
    

Formula

a(n) = C(n+7,8)*(-C(n+7,0) + 8*C(n+7,1) - 36*C(n+7,2) + 120*C(n+3,7) - 330*C(n+7,4) + 792*C(n+7,5) - 1716*C(n+7,6) + 3432*C(n+7,7))/6435. - Yahia Kahloune, Dec 22 2013
(n-1)^2*a(n) +(-2*n^2-10*n-37)*a(n-1) +(n+6)^2*a(n-2)=0. - R. J. Mathar, Dec 22 2013
G.f.: x*(x+1)*(x^6 +48*x^5 +393*x^4 +832*x^3 +393*x^2 +48*x +1)/(1-x)^16. - Colin Barker, May 02 2014
a(n) = (1/108972864000)*n*(1 + n)*(2 + n)*(3 + n)*(4 + n)*(5 + n)*(6 + n)*(7+n)*(7 + 2*n)*(60 + 64974*n + 126245*n^2 + 82467*n^3 + 23408*n^4 + 3003*n^5 + 143*n^6). - G. C. Greubel, Nov 22 2017

Extensions

More terms from Michel Marcus, Dec 22 2013

A086021 a(n) = Sum_{i=1..n} C(i+2,3)^3.

Original entry on oeis.org

1, 65, 1065, 9065, 51940, 227556, 820260, 2548260, 7040385, 17688385, 41082041, 89310585, 183506960, 359122960, 673554960, 1216893456, 2126746665, 3608290665, 5960927665, 9613191665, 15167828676, 23459298500, 35626298500, 53202298500, 78227501625, 113386110201
Offset: 1

Views

Author

André F. Labossière, Jul 11 2003

Keywords

Crossrefs

Programs

  • Magma
    [n^2*(-36 + 300*n + 1535*n^2 + 2700*n^3 + 2442*n^4 + 1260*n^5 + 375*n^6 + 60*n^7 + 4*n^8)/8640: n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Mathematica
    Table[n^2*(-36 + 300*n + 1535*n^2 + 2700*n^3 + 2442*n^4 + 1260*n^5 + 375*n^6 + 60*n^7 + 4*n^8)/8640, {n, 1, 30}] (* G. C. Greubel, Nov 22 2017 *)
  • PARI
    Vec(-x*(x^6+54*x^5+405*x^4+760*x^3+405*x^2+54*x+1)/(x-1)^11 + O(x^100)) \\ Colin Barker, May 02 2014
    
  • PARI
    for(n=1,30, print1(n^2*(-36 + 300*n + 1535*n^2 + 2700*n^3 + 2442*n^4 + 1260*n^5 + 375*n^6 + 60*n^7 + 4*n^8)/8640, ", ")) \\ G. C. Greubel, Nov 22 2017
    

Formula

a(n) = (C(n+3, 4)/1)*(1 +12*C(n-1, 1) +46*C(n-1, 2) +84*C(n-1, 3) +81*C(n-1, 4) +40*C(n-1, 5) +8*C(n-1, 6)). - Edited by Colin Barker, May 02 2014
G.f.: -x*(x^6 +54*x^5 +405*x^4 +760*x^3 +405*x^2 +54*x +1) / (x-1)^11. - Colin Barker, May 02 2014
a(n) = n^2*(-36 + 300*n + 1535*n^2 + 2700*n^3 + 2442*n^4 + 1260*n^5 + 375*n^6 + 60*n^7 + 4*n^8)/8640. - G. C. Greubel, Nov 22 2017
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