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 14 results. Next

A089664 a(n) = S2(n,1), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.

Original entry on oeis.org

0, 4, 41, 306, 1966, 11540, 63726, 336700, 1720364, 8562024, 41718190, 199753004, 942561636, 4392660376, 20253510956, 92519626200, 419201709976, 1885719209936, 8428262686254, 37453751742604, 165575219275700, 728534225415864, 3191850894862564
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S2(n, t): A003583 (t=0), this sequence (t=1), A089665 (t=2), A089666 (t=3), A089667 (t=4), A089668 (t=5).

Programs

  • Mathematica
    Table[(n*(3*n+5)*4^n -2*n*(n-1)*Binomial[2*n,n])/8, {n,0,40}] (* G. C. Greubel, May 25 2022 *)
  • PARI
    a(n)=n*(3*n+5)*2^(2*n-3) - 3*binomial(n+1,3)*binomial(2*n,n)/(n+1)/2 \\ Charles R Greathouse IV, Oct 23 2023
  • SageMath
    [(1/2)*(n*(3*n+5)*4^(n-1) -3*binomial(n+1, 3)*catalan_number(n)) for n in (0..40)] # G. C. Greubel, May 25 2022
    

Formula

a(n) = (1/8)*(n*(3*n+5)*4^n - 2*n*(n-1)*binomial(2*n, n)). (see Wang and Zhang, p. 338)
From G. C. Greubel, May 25 2022: (Start)
a(n) = (1/2)*( n*(3*n+5)*4^(n-1) - 3*binomial(n+1, 3)*Catalan(n) ).
G.f.: x*(4*(1-x) - 3*x*sqrt(1-4*x))/(1-4*x)^3.
E.g.f.: 2*x*(2 + 3*x)*exp(4*x) - (x^2/2)*(3*BesselI(0, 2*x) + 4*BesselI(1, 2*x) + BesselI(2, 2*x))*exp(2*x)). (End)

A089669 a(n) = S3(n,1), where S3(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^3.

Original entry on oeis.org

0, 8, 155, 2286, 29296, 344140, 3807774, 40327280, 413058080, 4120742808, 40242188170, 386141947972, 3650905945872, 34087726136672, 314844824466704, 2880757518523200, 26141327872575616, 235490128979282224, 2107598857648209954, 18752794473550896332
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S3(n, t): A007403 (t=0), this sequence (t=1), A089670 (t=2), A089671 (t=3), A089672 (t=4).

Programs

  • Mathematica
    a[n_]:= a[n]= Sum[k*(Sum[Binomial[n, j], {j,0,k}])^3, {k,0,n}];
    Table[a[n], {n,0,40}] (* G. C. Greubel, May 26 2022 *)
  • SageMath
    @CachedFunction
    def A089669(n): return sum(k*(sum(binomial(n,j) for j in (0..k)))^3 for k in (0..n))
    [A089669(n) for n in (0..40)] # G. C. Greubel, May 26 2022

Formula

a(n) = Sum_{k=0..n} k * (Sum_{j=0..k} binomial(n,j))^3. - G. C. Greubel, May 26 2022
From Vaclav Kotesovec, May 27 2022: (Start)
Recurrence: (n-3)*(n-2)*(n-1)*(81*n^5 - 1080*n^4 + 5769*n^3 - 15146*n^2 + 19080*n - 9088)*a(n) = (n-3)*(1863*n^7 - 29457*n^6 + 195435*n^5 - 696271*n^4 + 1410606*n^3 - 1569664*n^2 + 815328*n - 103936)*a(n-1) - 12*(1134*n^8 - 20709*n^7 + 162279*n^6 - 708529*n^5 + 1865571*n^4 - 2976218*n^3 + 2709336*n^2 - 1189824*n + 153600)*a(n-2) + 64*(405*n^8 - 7101*n^7 + 53712*n^6 - 228226*n^5 + 590469*n^4 - 934993*n^3 + 856278*n^2 - 392944*n + 65280)*a(n-3) + 256*(n-4)*(n-2)*(2*n - 7)*(81*n^5 - 675*n^4 + 2259*n^3 - 3509*n^2 + 2180*n - 384)*a(n-4).
a(n) ~ 3 * n^2 * 8^(n-1) * (1 - 1/sqrt(Pi*n) + (5/3 - 1/(2*Pi*sqrt(3)))/n). (End)

A089659 a(n) = S1(n,2), where S1(n, t) = Sum_{k=0..n} (k^t * Sum_{j=0..k} binomial(n,j)).

Original entry on oeis.org

0, 2, 19, 104, 440, 1600, 5264, 16128, 46848, 130560, 352000, 923648, 2369536, 5963776, 14766080, 36044800, 86900736, 207224832, 489357312, 1145569280, 2660761600, 6136266752, 14060355584, 32027705344, 72561459200, 163577856000, 367068708864, 820204535808
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S1(n, t): A001792 (t=0), A089658 (t=1), this sequence (t=2), A089660 (t=3), A089661 (t=4), A089662 (t=5), A089663 (t=6).

Programs

  • Magma
    I:=[0,2,19,104]; [n le 4 select I[n] else 8*Self(n-1)-24*Self(n-2)+32*Self(n-3)-16*Self(n-4): n in [1..41]]; // Vincenzo Librandi, Jun 22 2016
    
  • Mathematica
    LinearRecurrence[{8,-24,32,-16}, {0,2,19,104}, 40] (* Vincenzo Librandi, Jun 22 2016 *)
  • SageMath
    [2^(n-3)*n*(7*n^2 + 12*n + 5)/3 for n in (0..40)] # G. C. Greubel, May 24 2022

Formula

a(n) = 2^(n-3)*n*(7*n^2 + 12*n + 5)/3. (see Wang and Zhang p. 333)
From Chai Wah Wu, Jun 21 2016: (Start)
a(n) = 8*a(n-1) - 24*a(n-2) + 32*a(n-3) - 16*a(n-4) for n > 3.
G.f.: x*(2 + 3*x)/(1 - 2*x)^4. (End)
E.g.f.: x*(12 + 33*x + 14*x^2)*exp(2*x)/6. - Ilya Gutkovskiy, Jun 21 2016

A089660 a(n) = S1(n,3), where S1(n, t) = Sum_{k=0..n} (k^t * Sum_{j=0..k} binomial(n,j)).

Original entry on oeis.org

0, 2, 35, 276, 1522, 6820, 26664, 94640, 312512, 975744, 2913280, 8386048, 23416320, 63724544, 169637888, 443043840, 1137934336, 2879979520, 7194083328, 17761304576, 43390730240, 104997322752, 251881062400, 599482433536, 1416470986752, 3324615065600
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S1(n, t): A001792 (t=0), A089658 (t=1), A089659 (t=2), this sequence (t=3), A089661 (t=4), A089662 (t=5), A089663 (t=6).

Programs

  • Magma
    [2^(n-6)*n*(3*n*(7+10*n+5*n^2) -2): n in [0..40]]; // G. C. Greubel, May 24 2022
    
  • Mathematica
    LinearRecurrence[{10,-40,80,-80,32}, {0,2,35,276,1522}, 40] (* Vincenzo Librandi, Jun 22 2016 *)
  • SageMath
    [n*(15*n^3+30*n^2+21*n-2)*2^(n-6) for n in (0..40)] # G. C. Greubel, May 24 2022

Formula

a(n) = n*(15*n^3 + 30*n^2 + 21*n - 2)*2^(n-6). - R. J. Mathar, Sep 16 2009
G.f.: x*(2 + 15*x + 6*x^2 + 2*x^3)/(1-2*x)^5. - Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009
a(n) = 10*a(n-1) - 40*a(n-2) + 80*a(n-3) - 80*a(n-4) + 32*a(n-5) for n > 4. - Chai Wah Wu, Jun 21 2016
E.g.f.: x*(8 + 54*x + 60*x^2 + 15*x^3)*exp(2*x)/4. - Ilya Gutkovskiy, Jun 21 2016

A089661 a(n) = S1(n,4), where S1(n,t) = Sum_{k=0..n} k^t * Sum_{j=0..k} binomial(n,j).

Original entry on oeis.org

0, 2, 67, 764, 5492, 30304, 140672, 577920, 2167680, 7577088, 25037056, 79016960, 240028672, 705961984, 2019713024, 5641535488, 15431565312, 41438281728, 109462880256, 284942925824, 732004876288, 1858158460928, 4665915736064, 11600782163968, 28582042664960
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S1(n,t): A001792 (t=0), A089658 (t=1), A089659 (t=2), A089660 (t=3), this sequence (t=4), A089662 (t=5), A089663 (t=6).

Programs

  • Magma
    [2^(n-5)*n*(93*n^4+225*n^3+185*n^2+15*n-38)/15: n in [0..30]]; // Vincenzo Librandi, Jun 22 2016
    
  • Mathematica
    LinearRecurrence[{12,-60,160,-240,192,-64}, {0,2,67,764,5492,30304}, 40] (* Vincenzo Librandi, Jun 22 2016 *)
  • SageMath
    [n*(n+1)*(93*n^3 +132*n^2 +53*n -38)*2^(n-5)/15 for n in (0..40)] # G. C. Greubel, May 24 2022

Formula

a(n) = (1/15)*n*(n+1)*(93*n^3 + 132*n^2 + 53*n - 38)*2^(n-5). (See Wang and Zhang, p. 334)
From Chai Wah Wu, Jun 21 2016: (Start)
a(n) = 12*a(n-1) - 60*a(n-2) + 160*a(n-3) - 240*a(n-4) + 192*a(n-5) - 64*a(n-6) for n > 5.
G.f.: x*(2 + 43*x + 80*x^2 + 24*x^3)/(1 - 2*x)^6. (End)
a(n) = 2^(n-5)*n*(93*n^4 + 225*n^3 + 185*n^2 + 15*n - 38)/15. - Ilya Gutkovskiy, Jun 21 2016
E.g.f.: (1/30)*x*(60 + 885*x + 1930*x^2 + 1155*x^3 + 186*x^4)*exp(2*x). - G. C. Greubel, May 24 2022

A089662 a(n) = S1(n,5), where S1(n,t) = Sum_{k=0..n} k^t * Sum_{j=0..k} binomial(n,j).

Original entry on oeis.org

0, 2, 131, 2172, 20386, 138580, 763824, 3631712, 15470144, 60527232, 221297920, 765580288, 2529498624, 8039103488, 24713744384, 73818562560, 215011065856, 612515381248, 1710842904576, 4695105732608, 12682107944960, 33768108982272, 88748191645696
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S1(n,t): A001792 (t=0), A089658 (t=1), A089659 (t=2), A089660 (t=3), A089661 (t=4), this sequence (t=5), A089663 (t=6).

Programs

  • Magma
    [2^(n-7)*n*(21*n^5+61*n^4+55*n^3+15*n^2-28*n+4): n in [0..30]]; // Vincenzo Librandi, Jun 22 2016
    
  • Mathematica
    LinearRecurrence[{14,-84,280,-560,672,-448,128}, {0,2,131,2172,20386,138580, 763824}, 30] (* Vincenzo Librandi, Jun 22 2016 *)
  • SageMath
    [2^(n-7)*n*(21*n^5 +61*n^4 +55*n^3 +15*n^2 -28*n +4) for n in (0..40)] # G. C. Greubel, May 24 2022

Formula

There is an explicit formula for the sum - see Wang and Zhang, p. 334.
From Chai Wah Wu, Jun 21 2016: (Start)
a(n) = 14*a(n-1) - 84*a(n-2) + 280*a(n-3) - 560*a(n-4) + 672*a(n-5) - 448*a(n-6) + 128*a(n-7) for n > 6.
G.f.: x*(-16*x^5 + 64*x^4 + 422*x^3 + 506*x^2 + 103*x + 2)/(1 - 2*x)^7. (End)
a(n) = 2^(n-7)*n*(21*n^5 + 61*n^4 + 55*n^3 + 15*n^2 - 28*n + 4). - Ilya Gutkovskiy, Jun 21 2016
E.g.f.: (1/4)*x*(8 + 246*x + 940*x^2 + 1015*x^3 + 376*x^4 + 42*x^5)*exp(2*x). - G. C. Greubel, May 24 2022

A089663 a(n) = S1(n, 6), where S1(n, t) = Sum_{k=0..n} (k^t * Sum_{j=0..k} binomial(n,j)).

Original entry on oeis.org

0, 2, 259, 6284, 77180, 646960, 4235864, 23313408, 112793088, 493969920, 1998346240, 7577934848, 27232132096, 93517705216, 308908943360, 986642513920, 3059995508736, 9247515082752, 27310549696512, 79012328898560, 224396746424320, 626707269681152
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S1(n, t): A001792 (t=0), A089658 (t=1), A089659 (t=2), A089660 (t=3), A089661 (t=4), A089662 (t=5), this sequence (t=6).

Programs

  • Magma
    [2^(n-7)*n*(381*n^6+1302*n^5+1302*n^4+420*n^3-707*n^2-378*n+368)/21: n in [0..40]]; // G. C. Greubel, May 24 2022
    
  • Mathematica
    LinearRecurrence[{16,-112,448,-1120,1792,-1792,1024,-256}, {0, 2, 259, 6284, 77180, 646960, 4235864, 23313408}, 40] (* G. C. Greubel, Jun 22 2016 *)
  • SageMath
    [n*(n+1)*(381*n^5 +921*n^4 +381*n^3 +39*n^2 -746*n +368)*2^(n-7)/21 for n in (0..40)] # G. C. Greubel, May 24 2022

Formula

a(n) = (1/21)*n*(n+1)*(381*n^5 + 921*n^4 + 381*n^3 + 39*n^2 - 746*n + 368) * 2^(n-7). (See Wang and Zhang, p. 334.)
From Chai Wah Wu, Jun 21 2016: (Start)
a(n) = 16*a(n-1) - 112*a(n-2) + 448*a(n-3) - 1120*a(n-4) + 1792*a(n-5) - 1792*a(n-6) + 1024*a(n-7) - 256*a(n-8) for n > 7.
G.f.: x*(2 + 227*x + 2364*x^2 + 4748*x^3 + 2096*x^4 - 72*x^5)/(1 - 2*x)^8. (End)
a(n) = 2^(n-7)*n*(381*n^6 + 1302*n^5 + 1302*n^4 + 420*n^3 - 707*n^2 - 378*n + 368)/21. - Ilya Gutkovskiy, Jun 21 2016
E.g.f.: (1/42)*x*(84 + 5271*x + 33278*x^2 + 57855*x^3 + 37086*x^4 + 9303*x^5 +
762*x^6)*exp(2*x). - G. C. Greubel, May 24 2022

A089665 a(n) = S2(n,2), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.

Original entry on oeis.org

0, 4, 73, 788, 6630, 48120, 316526, 1940568, 11284380, 62968560, 339954670, 1786320184, 9176663028, 46248446608, 229285525420, 1120646918000, 5409322603896, 25824570392544, 122086747617198, 572130452101240, 2660063893120900, 12279619924999504, 56318986959592676
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S2(n, t): A003583 (t=0), A089664 (t=1), this sequence (t=2), A089666 (t=3), A089667 (t=4), A089668 (t=5).

Programs

  • Maple
    S2:= (n, t) -> add(k^t*add(binomial(n, j), j = 0..k)^2, k = 0..n);
    seq(S2(n, 2), n = 0..40);
  • Mathematica
    Table[(1/24)*(n*(n+1)*(7*n+5)*4^n -4*(n-1)*(3*n^2-2*n+1)*Binomial[2*n-2, n-1]), {n,0,40}] (* G. C. Greubel, May 25 2022 *)
  • SageMath
    [(n/6)*((n+1)*(7*n+5)*4^(n-1) -(n-1)*(3*n^2-2*n+1)*catalan_number(n-1)) for n in (0..40)] # G. C. Greubel, May 25 2022

Formula

a(n) = (1/24)*n*( (n+1)*(7*n+5)*4^n - 2*(n-1)*(3*n^2 - 2*n + 1)*binomial(2*n, n)/(2*n-1) ). (See Wang and Zhang, p. 338.)
From G. C. Greubel, May 25 2022: (Start)
a(n) = (n/6)*( (n+1)*(7*n+5)*4^(n-1) - (n-1)*(3*n^2 - 2*n + 1)*Catalan(n-1) ).
G.f.: x*(4*(1+3*x) - x*(3 + 2*x + 4*x^2)*sqrt(1-4*x))/(1-4*x)^4.
E.g.f.: x*(4 + 22*x + 56*x^2/3)*exp(4*x) + (x^2/6)*exp(2*x)*( -(9 + 62*x + 145*x^2 + 84*x^3)*f(x, 0) + (36 + 99*x - 32*x^2 - 84 x^3)*f(x, 1) + (45 + 270*x + 284*x^2 + 48*x^3)*f(x, 2) + x*(109 + 224*x + 78*x^2)*f(x, 3) + x^2*(53 + 36*x)*f(x, 4) + 6*x^3*f(x, 5) ), where f(x, n) = BesselI(n, 2*x). (End)

A089666 a(n) = S2(n,3), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.

Original entry on oeis.org

0, 4, 137, 2136, 23452, 209840, 1640346, 11648224, 76976048, 481048128, 2874897670, 16564931504, 92584313112, 504313834336, 2687067833492, 14045889333120, 72202366588096, 365713117287680, 1828223537042142, 9032706189007888, 44158716127799240, 213826835772518304
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S2(n, t): A003583 (t=0), A089664 (t=1), A089665 (t=2), this sequence (t=3), A089667 (t=4), A089668 (t=5).

Programs

  • Maple
    S2:= (n, t) -> add(k^t*add(binomial(n, j), j = 0..k)^2, k = 0..n);
    seq(S2(n, 3), n = 0..40);
  • Mathematica
    Table[n*(15*n^3+30*n^2+21*n-2)*4^(n-3) -(n-1)^2*n^2*(n+1)*Binomial[2*n,n]/(8*(2*n -1)), {n, 0, 40}] (* G. C. Greubel, May 25 2022 *)
  • SageMath
    [n*(15*n^3+30*n^2+21*n-2)*4^(n-3) - 9*binomial(n+1, 3)^2 * catalan_number(n-1)/(n+1) for n in (0..40)] # G. C. Greubel, May 25 2022

Formula

a(n) = n*(15*n^3 + 30*n^2 + 21*n - 2)*4^(n-3) - (n-1)^2*n^2*(n+1)*binomial(2*n, n)/(8*(2*n-1)). (See Wang and Zhang, p. 338.)
From G. C. Greubel, May 25 2022: (Start)
a(n) = n*(15*n^3 + 30*n^2 + 21*n - 2)*4^(n-3) - 9*binomial(n+1, 3)^2 * Catalan(n- 1)/(n+1).
G.f.: x*(4*(1 + 15*x + 12*x^2 + 8*x^3) - 3*x*(1 + 6*x - 6*x^2 + 4*x^3)*sqrt(1-4*x))/(1-4*x)^5. (End)

Extensions

Name changed by G. C. Greubel, May 25 2022

A089667 a(n) = S2(n,4), where S2(n, t) = Sum_{k=0..n} k^t *(Sum_{j=0..k} binomial(n,j))^2.

Original entry on oeis.org

0, 4, 265, 5984, 85722, 944904, 8771462, 72095520, 541127988, 3785356752, 25032083230, 158102986624, 961123994220, 5656943319664, 32386277835772, 181019819948864, 990793669704552, 5323620638111136, 28137973407708174, 146552649537716992
Offset: 0

Views

Author

N. J. A. Sloane, Jan 04 2004

Keywords

Crossrefs

Sequences of S2(n, t): A003583 (t=0), A089664 (t=1), A089665 (t=2), A089666 (t=3), this sequence (t=4), A089668 (t=5).

Programs

  • Mathematica
    Table[(1/30)*(n*(n+1)*(93*n^3+132*n^2+53*n-38)*4^(n-2) -(n-1)*(15*n^5-99*n^3 + 116*n^2-34*n+6)*CatalanNumber[n-2]), {n,0,40}] (* G. C. Greubel, May 25 2022 *)
    CoefficientList[Series[x*( 4*(1 + 43*x + 160*x^2 + 96*x^3) - x*(3 + 62*x - 72*x^2 + 96*x^3 - 224*x^4 + 144*x^5)*Sqrt[1-4*x] )/(1-4*x)^6, {x,0,35}], x] (* Georg Fischer, Nov 09 2022 *)
  • SageMath
    [(1/30)*(n*(n+1)*(93*n^3+132*n^2+53*n-38)*4^(n-2) - (n-1)*(15*n^5 - 99*n^3+116*n^2-34*n+6)*catalan_number(n-2) ) for n in (0..40)] # G. C. Greubel, May 25 2022

Formula

a(n) = (1/480)*( n*(n+1)*(93*n^3 + 132*n^2 + 53*n - 38)*4^n - 4*n*(n-1)*(15*n^5 - 99*n^3 + 116*n^2 - 34*n + 6)*binomial(2*n, n)/((2*n-1)*(2*n-3)) ). (See Wang and Zhang, p. 338.)
From G. C. Greubel, May 25 2022: (Start)
a(n) = (1/30)*( n*(n+1)*(93*n^3 + 132*n^2 + 53*n - 38)*4^(n-2) - (n-1)*(15*n^5 - 99*n^3 + 116*n^2 - 34*n + 6)*Catalan(n-2) ).
G.f.: x*( 4*(1 + 43*x + 160*x^2 + 96*x^3) - x*(3 + 62*x - 72*x^2 + 96*x^3 - 224*x^4 + 144*x^5)*sqrt(1-4*x) )/(1-4*x)^6. [Typo corrected by Georg Fischer, Nov 09 2022] (End)
Showing 1-10 of 14 results. Next