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.

User: Alejandro J. Becerra Jr.

Alejandro J. Becerra Jr.'s wiki page.

Alejandro J. Becerra Jr. has authored 6 sequences.

A318159 Figurate numbers based on the small stellated dodecahedron: a(n) = n*(21*n^2 - 33*n + 14)/2.

Original entry on oeis.org

1, 32, 156, 436, 935, 1716, 2842, 4376, 6381, 8920, 12056, 15852, 20371, 25676, 31830, 38896, 46937, 56016, 66196, 77540, 90111, 103972, 119186, 135816, 153925, 173576, 194832, 217756, 242411, 268860, 297166, 327392, 359601, 393856, 430220, 468756, 509527
Offset: 1

Author

Keywords

Comments

The small stellated dodecahedron is a 3D nonconvex regular polyhedron represented by the Schlaefli symbol {5/2, 5}.
When truncated, a degenerate dodecahedron is produced. It is then easy to recognize that every small stellated dodecahedron can be constructed by morphing the 12 pentagonal faces of a regular dodecahedron into pentagonal pyramids.
The last digits form a cycle of length 20 [1, 2, 6, 6, ..., 1, 2, 6, 6].

Crossrefs

Programs

  • Magma
    [n*(21*n^2-33*n+14)/2: n in [1..40]]; // Vincenzo Librandi, Aug 27 2018
  • Mathematica
    Table[(n (14 - 33 n + 21 n^2)) / 2, {n, 45}] (* Vincenzo Librandi, Aug 27 2018 *)
    CoefficientList[Series[(1 + 28*x + 34*x^2) / (1 - x)^4 , {x, 0, 45}], x] (* or *)
    LinearRecurrence[{4, -6, 4, -1}, {1, 32, 156, 436}, 45] (* Stefano Spezia, Sep 02 2018 *)
  • PARI
    Vec(x*(1 + 28*x + 34*x^2) / (1 - x)^4 + O(x^40)) \\ Colin Barker, Aug 20 2018
    
  • PARI
    a(n) = (n*(14 - 33*n + 21*n^2)) / 2 \\ Colin Barker, Aug 20 2018
    

Formula

a(n) = A006566(n) + 12*A002411(n-1).
a(n) == a(n+20) (mod 10).
From Colin Barker, Aug 20 2018: (Start)
G.f.: x*(1 + 28*x + 34*x^2)/(1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>4. (End)
E.g.f.: exp(x)*x*(2 + 30*x + 21*x^2)/2. - Elmo R. Oliveira, Aug 22 2025

Extensions

More terms from Colin Barker, Aug 20 2018

A300624 Figurate numbers based on the 11-dimensional regular convex polytope called the 11-dimensional cross-polytope, or 11-dimensional hyperoctahedron.

Original entry on oeis.org

0, 1, 22, 243, 1804, 10165, 46530, 180775, 614680, 1871145, 5188590, 13286043, 31760676, 71513949, 152784282, 311603535, 609802800, 1150082385, 2098144710, 3714481475, 6399123260, 10753517061, 17664712562, 28418229623, 44847366984, 69528316025, 106032285086
Offset: 0

Author

Keywords

Comments

The 11-dimensional cross-polytope is represented by the Schlaefli symbol {3, 3, 3, 3, 3, 3, 3, 3, 3, 4}. It is the dual of the 11-dimensional hypercube.

Crossrefs

Similar sequences: A005900 (m=3), A014820(n-1) (m=4), A069038 (m=5), A069039 (m=6), A099193 (m=7), A099195 (m=8), A099196 (m=9), A099197 (m=10).

Programs

  • Magma
    [(n*(14175 + 83754*n^2 + 50270*n^4 + 7392*n^6 + 330*n^8 + 4*n^10)) / 155925 : n in [0..40]]; // Wesley Ivan Hurt, Jul 17 2020
  • PARI
    concat(0, Vec(x*(1 + x)^10 / (1 - x)^12 + O(x^40))) \\ Colin Barker, Aug 15 2018
    
  • PARI
    a(n) = (n*(14175 + 83754*n^2 + 50270*n^4 + 7392*n^6 + 330*n^8 + 4*n^10)) / 155925 \\ Colin Barker, Aug 15 2018
    

Formula

a(n) = 11-crosspolytope(n).
From Colin Barker, Aug 15 2018: (Start)
G.f.: x*(1 + x)^10 / (1 - x)^12.
a(n) = (n*(14175 + 83754*n^2 + 50270*n^4 + 7392*n^6 + 330*n^8 + 4*n^10)) / 155925.
(End)

A302562 Partial sums of A092181.

Original entry on oeis.org

1, 25, 178, 722, 2147, 5243, 11172, 21540, 38469, 64669, 103510, 159094, 236327, 340991, 479816, 660552, 892041, 1184289, 1548538, 1997338, 2544619, 3205763, 3997676, 4938860, 6049485, 7351461, 8868510, 10626238, 12652207, 14976007, 17629328, 20646032
Offset: 1

Author

Keywords

Comments

Geometrically, the partial sums of A092181 may be interpreted as 5-dimensional icositetrachoronal hyperpyramidal numbers. The icositetrachoron is a convex regular 4-D polytope with Schlaefli symbol {3,4,3}.

Crossrefs

Cf. A092181.

Programs

  • Mathematica
    Table[n*(7 - 10*n^2 + 15*n^3 + 18*n^4)/30, {n, 40}] (* Wesley Ivan Hurt, Oct 30 2022 *)
  • PARI
    Vec(x*(1 + 19*x + 43*x^2 + 9*x^3) / (1 - x)^6 + O(x^40)) \\ Colin Barker, Aug 15 2018
    
  • PARI
    a(n) = (n*(7 - 10*n^2 + 15*n^3 + 18*n^4)) / 30 \\ Colin Barker, Aug 15 2018

Formula

a(n) = Sum_{k=1..n} A092181(k).
From Colin Barker, Aug 15 2018: (Start)
G.f.: x*(1 + 19*x + 43*x^2 + 9*x^3) / (1 - x)^6.
a(n) = n*(7 - 10*n^2 + 15*n^3 + 18*n^4) / 30.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)

A302561 Partial sums of A092182.

Original entry on oeis.org

1, 121, 1068, 4720, 14705, 36981, 80416, 157368, 284265, 482185, 777436, 1202136, 1794793, 2600885, 3673440, 5073616, 6871281, 9145593, 11985580, 15490720, 19771521, 24950101, 31160768, 38550600, 47280025, 57523401, 69469596, 83322568, 99301945
Offset: 1

Author

Keywords

Comments

Geometrically, the partial sums of A092182 may be interpreted as 5-dimensional hexacosichoronal hyperpyramidal numbers. The hexacosichoron is a convex regular 4-D polytope with Schlaefli symbol {3,3,5}.

Crossrefs

Cf. A092182.

Programs

  • Mathematica
    Accumulate[LinearRecurrence[{5,-10,10,-5,1},{1,120,947,3652,9985},30]] (* or *) LinearRecurrence[ {6,-15,20,-15,6,-1},{1,121,1068,4720,14705,36981},30] (* Harvey P. Dale, May 04 2024 *)
  • PARI
    Vec(x*(1 + 115*x + 357*x^2 + 107*x^3) / (1 - x)^6 + O(x^40)) \\ Colin Barker, Aug 15 2018
    
  • PARI
    a(n) = (n*(12 + n - 64*n^2 + 5*n^3 + 58*n^4)) / 12 \\ Colin Barker, Aug 15 2018

Formula

a(n) = Sum_{k=1..n} A092182(k).
From Colin Barker, Aug 15 2018: (Start)
G.f.: x*(1 + 115*x + 357*x^2 + 107*x^3) / (1 - x)^6.
a(n) = (n*(12 + n - 64*n^2 + 5*n^3 + 58*n^4)) / 12.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)

A302560 Partial sums of icosahedral numbers (A006564).

Original entry on oeis.org

1, 13, 61, 185, 440, 896, 1638, 2766, 4395, 6655, 9691, 13663, 18746, 25130, 33020, 42636, 54213, 68001, 84265, 103285, 125356, 150788, 179906, 213050, 250575, 292851, 340263, 393211, 452110, 517390, 589496, 668888, 756041, 851445, 955605, 1069041, 1192288, 1325896
Offset: 1

Author

Keywords

Comments

Geometrically, the partial sums of A006564 may be interpreted as 4-dimensional icosahedral hyperpyramidal numbers.

Crossrefs

Cf. A006564.

Programs

  • PARI
    Vec(x*(1 + 8*x + 6*x^2) / (1 - x)^5 + O(x^40)) \\ Colin Barker, Aug 15 2018
    
  • PARI
    a(n) = (n*(2 - 3*n + 10*n^2 + 15*n^3)) / 24 \\ Colin Barker, Aug 15 2018

Formula

a(n) = Sum_{k=1..n} A006564(k).
From Colin Barker, Aug 15 2018: (Start)
G.f.: x*(1 + 8*x + 6*x^2) / (1 - x)^5.
a(n) = n*(2 - 3*n + 10*n^2 + 15*n^3)/24.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)

A302559 Partial sums of A092183.

Original entry on oeis.org

1, 601, 5584, 25052, 78557, 198233, 431928, 846336, 1530129, 2597089, 4189240, 6479980, 9677213, 14026481, 19814096, 27370272, 37072257, 49347465, 64676608, 83596828, 106704829, 134660009, 168187592, 208081760, 255208785, 310510161
Offset: 1

Author

Keywords

Comments

Geometrically, the partial sums of A092183 may be interpreted as 5-dimensional hecatonicosachoronal hyperpyramidal numbers. The hecatonicosachoron is a convex regular 4-D polytope with Schlaefli symbol {5,3,3}.

Crossrefs

Cf. A092183.

Programs

  • PARI
    Vec(x*(1 + 595*x + 1993*x^2 + 543*x^3) / (1 - x)^6 + O(x^40)) \\ Colin Barker, Aug 15 2018
    
  • PARI
    a(n) = (n*(584 - 105*n - 2120*n^2 + 135*n^3 + 1566*n^4)) / 60 \\ Colin Barker, Aug 15 2018

Formula

a(n) = Sum_{k=1..n} A092183(k).
From Colin Barker, Aug 15 2018: (Start)
G.f.: x*(1 + 595*x + 1993*x^2 + 543*x^3) / (1 - x)^6.
a(n) = n*(584 - 105*n - 2120*n^2 + 135*n^3 + 1566*n^4)/60.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6. (End)