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 15 results. Next

A341794 Number of ways to write n as an ordered sum of 3 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 3, 0, 0, 3, 0, 0, 4, 0, 0, 6, 0, 0, 3, 0, 0, 3, 3, 0, 3, 6, 0, 0, 3, 0, 1, 6, 0, 0, 6, 0, 0, 3, 0, 0, 9, 3, 0, 3, 3, 0, 6, 0, 0, 6, 3, 0, 0, 0, 0, 3, 6, 0, 3, 6, 1, 6, 0, 0, 3, 6, 0, 6, 0, 0, 6, 3, 0, 0, 3, 3, 3, 6, 0, 0, 9, 0, 0, 0, 0, 0, 9, 0, 0, 6, 3, 0, 9, 0, 0, 12
Offset: 3

Views

Author

Ilya Gutkovskiy, Feb 19 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 95; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^3, {x, 0, nmax}], x] // Drop[#, 3] &

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^3.

A341796 Number of ways to write n as an ordered sum of 5 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 5, 0, 0, 10, 0, 0, 15, 0, 0, 25, 0, 0, 31, 0, 0, 30, 5, 0, 35, 20, 0, 30, 30, 0, 20, 40, 0, 20, 65, 0, 10, 65, 0, 5, 70, 10, 5, 90, 30, 0, 70, 30, 1, 85, 40, 0, 80, 60, 0, 50, 50, 0, 70, 90, 10, 50, 90, 20, 50, 80, 10, 60, 130, 20, 65, 70, 20, 65, 90, 30, 50, 110, 70, 65, 100
Offset: 5

Views

Author

Ilya Gutkovskiy, Feb 19 2021

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 100);
    Coefficients(R!( (&+[x^Binomial(j+2,3): j in [1..20]])^5 )); // G. C. Greubel, Jul 20 2022
    
  • Mathematica
    nmax = 82; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^5, {x, 0, nmax}], x] // Drop[#, 5] &
  • SageMath
    def f(m, x): return ( sum( x^(binomial(j+2,3)) for j in (1..20) ) )^m
    def A341796_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(5, x) ).list()
    a=A341796_list(120); a[5:100] # G. C. Greubel, Jul 20 2022

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^5.

A341797 Number of ways to write n as an ordered sum of 6 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 6, 0, 0, 15, 0, 0, 26, 0, 0, 45, 0, 0, 66, 0, 0, 76, 6, 0, 90, 30, 0, 96, 60, 0, 80, 90, 0, 75, 150, 0, 60, 192, 0, 35, 210, 15, 30, 270, 60, 15, 270, 90, 6, 270, 120, 6, 306, 195, 0, 240, 210, 1, 246, 270, 20, 240, 360, 60, 180, 330, 60, 216, 450, 80, 210, 435, 120, 216, 360
Offset: 6

Views

Author

Ilya Gutkovskiy, Feb 19 2021

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 80);
    Coefficients(R!( (&+[x^Binomial(j+2,3): j in [1..20]])^6 )); // G. C. Greubel, Jul 20 2022
    
  • Mathematica
    nmax = 77; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^6, {x, 0, nmax}], x] // Drop[#, 6] &
  • SageMath
    def f(m, x): return ( sum( x^(binomial(j+2,3)) for j in (1..20) ) )^m
    def A341797_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(6, x) ).list()
    a=A341797_list(100); a[6:81] # G. C. Greubel, Jul 20 2022

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^6.

A341795 Number of ways to write n as an ordered sum of 4 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 4, 0, 0, 6, 0, 0, 8, 0, 0, 13, 0, 0, 12, 0, 0, 10, 4, 0, 12, 12, 0, 6, 12, 0, 4, 16, 0, 4, 24, 0, 0, 16, 0, 1, 24, 6, 0, 24, 12, 0, 16, 6, 0, 28, 12, 0, 12, 12, 0, 12, 12, 0, 16, 30, 4, 12, 12, 4, 16, 24, 0, 16, 24, 4, 24, 6, 0, 12, 24, 12, 12, 18, 12, 13, 36, 0, 0, 24, 12
Offset: 4

Views

Author

Ilya Gutkovskiy, Feb 19 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 85; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^4, {x, 0, nmax}], x] // Drop[#, 4] &

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^4.

A322340 Number of compositions (ordered partitions) of n into square pyramidal numbers (A000330).

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 8, 11, 15, 20, 27, 36, 48, 64, 85, 114, 153, 205, 274, 365, 487, 651, 871, 1165, 1557, 2080, 2780, 3716, 4967, 6639, 8873, 11860, 15853, 21189, 28320, 37850, 50589, 67618, 90379, 120799, 161456, 215797, 288430, 385512, 515269, 688699
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 26 2018

Keywords

Crossrefs

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, (t->
          `if`(t*(t+1)*(2*t+1)/6>n, t-1, t))(1+h(n-1)))
        end:
    a:= proc(n) option remember; `if`(n=0, 1,
          add(a(n-i*(i+1)*(2*i+1)/6), i=1..h(n)))
        end:
    seq(a(n), n=0..60);  # Alois P. Heinz, Dec 28 2018
  • Mathematica
    nmax = 49; CoefficientList[Series[1/(1 - Sum[x^(k (k + 1) (2 k + 1)/6), {k, 1, nmax}]), {x, 0, nmax}], x]

Formula

G.f.: 1/(1 - Sum_{k>=1} x^(k*(k+1)*(2*k+1)/6)).

A341806 Number of ways to write n as an ordered sum of 7 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 7, 0, 0, 21, 0, 0, 42, 0, 0, 77, 0, 0, 126, 0, 0, 168, 7, 0, 211, 42, 0, 252, 105, 0, 252, 182, 0, 245, 315, 0, 231, 469, 0, 175, 574, 21, 140, 735, 105, 105, 854, 210, 56, 875, 315, 42, 987, 525, 21, 952, 693, 7, 882, 840, 42, 924, 1155, 140, 770, 1260, 211, 749, 1470
Offset: 7

Views

Author

Ilya Gutkovskiy, Feb 20 2021

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 80);
    Coefficients(R!( (&+[x^Binomial(j+2,3): j in [1..20]])^7 )); // G. C. Greubel, Jul 19 2022
    
  • Mathematica
    nmax = 72; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^7, {x, 0, nmax}], x] // Drop[#, 7] &
  • SageMath
    def f(m, x): return ( sum( x^(binomial(j+2,3)) for j in (1..20) ) )^m
    def A341806_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(7, x) ).list()
    a=A341806_list(100); a[7:81] # G. C. Greubel, Jul 19 2022

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^7.

A341807 Number of ways to write n as an ordered sum of 8 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 8, 0, 0, 28, 0, 0, 64, 0, 0, 126, 0, 0, 224, 0, 0, 336, 8, 0, 456, 56, 0, 589, 168, 0, 672, 336, 0, 708, 616, 0, 728, 1016, 0, 658, 1400, 28, 560, 1856, 168, 476, 2352, 420, 336, 2632, 728, 238, 2968, 1260, 168, 3192, 1904, 84, 3096, 2464, 112, 3192, 3360, 308, 3024, 4144
Offset: 8

Views

Author

Ilya Gutkovskiy, Feb 20 2021

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 80);
    Coefficients(R!( (&+[x^Binomial(j+2,3): j in [1..70]])^8 )); // G. C. Greubel, Jul 19 2022
    
  • Mathematica
    nmax = 70; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^8, {x, 0, nmax}], x] // Drop[#, 8] &
  • SageMath
    def f(m, x): return ( sum( x^(binomial(j+2,3)) for j in (1..8) ) )^m
    def A341807_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(8, x) ).list()
    a=A341807_list(100); a[8:81] # G. C. Greubel, Jul 19 2022

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^8.

A341808 Number of ways to write n as an ordered sum of 9 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 9, 0, 0, 36, 0, 0, 93, 0, 0, 198, 0, 0, 378, 0, 0, 624, 9, 0, 918, 72, 0, 1269, 252, 0, 1597, 576, 0, 1836, 1134, 0, 2025, 2025, 0, 2058, 3096, 36, 1926, 4356, 252, 1764, 5877, 756, 1470, 7182, 1512, 1134, 8388, 2772, 882, 9576, 4608, 588, 10035, 6552, 462
Offset: 9

Views

Author

Ilya Gutkovskiy, Feb 20 2021

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 70);
    Coefficients(R!( (&+[x^Binomial(j+2,3): j in [1..70]])^9 )); // G. C. Greubel, Jul 18 2022
    
  • Mathematica
    nmax = 66; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^9, {x, 0, nmax}], x] // Drop[#, 9] &
  • SageMath
    def f(m, x): return ( sum( x^(binomial(j+2,3)) for j in (1..8) ) )^m
    def A341808_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(9, x) ).list()
    a=A341808_list(100); a[9:71] # G. C. Greubel, Jul 18 2022

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^9.

A341809 Number of ways to write n as an ordered sum of 10 nonzero tetrahedral numbers.

Original entry on oeis.org

1, 0, 0, 10, 0, 0, 45, 0, 0, 130, 0, 0, 300, 0, 0, 612, 0, 0, 1095, 10, 0, 1740, 90, 0, 2565, 360, 0, 3490, 930, 0, 4351, 1980, 0, 5130, 3790, 0, 5680, 6330, 45, 5820, 9540, 360, 5715, 13620, 1260, 5292, 17950, 2880, 4530, 22140, 5670, 3780, 26490, 10170, 2940, 29770, 15840
Offset: 10

Views

Author

Ilya Gutkovskiy, Feb 20 2021

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 70);
    Coefficients(R!( (&+[x^Binomial(j+2,3): j in [1..70]])^10 )); // G. C. Greubel, Jul 18 2022
    
  • Mathematica
    nmax = 66; CoefficientList[Series[Sum[x^Binomial[k + 2, 3], {k, 1, nmax}]^10, {x, 0, nmax}], x] // Drop[#, 10] &
  • Sage
    def f(m, x): return ( sum( x^(binomial(j+2,3)) for j in (1..8) ) )^m
    def A341809_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( f(10, x) ).list()
    a=A341809_list(100); a[10:71]  # G. C. Greubel, Jul 18 2022

Formula

G.f.: ( Sum_{k>=1} x^binomial(k+2,3) )^10.

A303170 Number of ordered ways of writing n as a sum of n tetrahedral numbers.

Original entry on oeis.org

1, 1, 1, 1, 5, 21, 61, 141, 309, 757, 2111, 6051, 16721, 44617, 118301, 318501, 871781, 2400741, 6596953, 18067329, 49460555, 135697395, 373271515, 1028451579, 2835353337, 7819016521, 21572619771, 59562583471, 164586609409, 455114644297, 1259191262441, 3485551053561
Offset: 0

Views

Author

Ilya Gutkovskiy, Apr 19 2018

Keywords

Crossrefs

Main diagonal of A290429.

Programs

  • Mathematica
    Table[SeriesCoefficient[Sum[x^(k (k + 1) (k + 2)/6), {k, 0, n}]^n, {x, 0, n}], {n, 0, 31}]

Formula

a(n) = [x^n] (Sum_{k>=0} x^(k*(k+1)*(k+2)/6))^n.
a(n) = A290429(n,n).
Showing 1-10 of 15 results. Next