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 1-5 of 5 results.

A327605 Number of parts in all twice partitions of n where both partitions are strict.

Original entry on oeis.org

0, 1, 1, 5, 8, 15, 28, 49, 86, 156, 259, 412, 679, 1086, 1753, 2826, 4400, 6751, 10703, 16250, 24757, 38047, 57459, 85861, 129329, 192660, 286177, 424358, 624510, 915105, 1347787, 1961152, 2847145, 4144089, 5988205, 8638077, 12439833, 17837767, 25536016
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2019

Keywords

Examples

			a(3) = 5 = 1+2+2 counting the parts in 3, 21, 2|1.
		

Crossrefs

Programs

  • Maple
    g:= proc(n, i) option remember; `if`(i*(i+1)/2 f+
           [0, f[1]])(g(n-i, min(n-i, i-1)))))
        end:
    b:= proc(n, i) option remember; `if`(i*(i+1)/2 (f-> f+[0, f[1]*
           h[2]/h[1]])(b(n-i, min(n-i, i-1))*h[1]))(g(i$2))))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=0..42);
  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = With[{}, If[n == 0, Return@{1, 0}]; If[k == 0, Return@{1, 1}]; If[i (i + 1)/2 < n, Return@{0, 0}]; b[n, i - 1, k] + Function[h, Function[f, f + {0, f[[1]] h[[2]]/h[[1]]}][h[[1]] b[n - i, Min[n - i, i - 1], k]]][b[i, i, k - 1]]];
    a[n_] := b[n, n, 2][[2]];
    a /@ Range[0, 42] (* Jean-François Alcover, Jun 03 2020, after Alois P. Heinz in A327622 *)

A327618 Number A(n,k) of parts in all k-times partitions of n; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

0, 0, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 5, 6, 1, 0, 1, 7, 14, 12, 1, 0, 1, 9, 25, 44, 20, 1, 0, 1, 11, 39, 109, 100, 35, 1, 0, 1, 13, 56, 219, 315, 274, 54, 1, 0, 1, 15, 76, 386, 769, 1179, 581, 86, 1, 0, 1, 17, 99, 622, 1596, 3643, 3234, 1417, 128, 1, 0, 1, 19, 125, 939, 2960, 9135, 12336, 10789, 2978, 192, 1
Offset: 0

Views

Author

Alois P. Heinz, Sep 19 2019

Keywords

Comments

Row n is binomial transform of the n-th row of triangle A327631.

Examples

			A(2,2) = 5 = 1+2+2 counting the parts in 2, 11, 1|1.
Square array A(n,k) begins:
  0,  0,   0,    0,     0,     0,     0,      0, ...
  1,  1,   1,    1,     1,     1,     1,      1, ...
  1,  3,   5,    7,     9,    11,    13,     15, ...
  1,  6,  14,   25,    39,    56,    76,     99, ...
  1, 12,  44,  109,   219,   386,   622,    939, ...
  1, 20, 100,  315,   769,  1596,  2960,   5055, ...
  1, 35, 274, 1179,  3643,  9135, 19844,  38823, ...
  1, 54, 581, 3234, 12336, 36911, 93302, 208377, ...
		

Crossrefs

Columns k=0-3 give: A057427, A006128, A327594, A327627.
Rows n=0-3 give: A000004, A000012, A005408, A095794(k+1).
Main diagonal gives A327619.

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(n=0, [1, 0],
         `if`(k=0, [1, 1], `if`(i<2, 0, b(n, i-1, k))+
             (h-> (f-> f +[0, f[1]*h[2]/h[1]])(h[1]*
            b(n-i, min(n-i, i), k)))(b(i$2, k-1))))
        end:
    A:= (n, k)-> b(n$2, k)[2]:
    seq(seq(A(n, d-n), n=0..d), d=0..14);
  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[n == 0, {1, 0}, If[k == 0, {1, 1}, If[i < 2, 0, b[n, i - 1, k]] + Function[h, Function[f, f + {0, f[[1]] h[[2]]/ h[[1]]}][h[[1]] b[n - i, Min[n - i, i], k]]][b[i, i, k - 1]]]];
    A[n_, k_] := b[n, n, k][[2]];
    Table[A[n, d-n], {d, 0, 14}, {n, 0, d}] // Flatten (* Jean-François Alcover, Apr 30 2020, after Alois P. Heinz *)

Formula

A(n,k) = Sum_{i=0..k} binomial(k,i) * A327631(n,i).

A327607 Number of parts in all twice partitions of n where the first partition is strict.

Original entry on oeis.org

0, 1, 3, 11, 21, 58, 128, 276, 516, 1169, 2227, 4324, 8335, 15574, 29116, 55048, 97698, 176291, 323277, 563453, 1005089, 1770789, 3076868, 5293907, 9184885, 15668638, 26751095, 45517048, 76882920, 128738414, 217219751, 360525590, 599158211, 995474365
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2019

Keywords

Examples

			a(3) = 11 = 1+2+3+2+3 counting the parts in 3, 21, 111, 2|1, 11|1.
		

Crossrefs

Programs

  • Maple
    g:= proc(n) option remember; (p-> [p(n), add(p(n-j)*
          numtheory[tau](j), j=1..n)])(combinat[numbpart])
        end:
    b:= proc(n, i) option remember; `if`(i*(i+1)/2 (f-> f+[0, f[1]*
           h[2]/h[1]])(b(n-i, min(n-i, i-1))*h[1]))(g(i))))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=0..37);
  • Mathematica
    g[n_] := g[n] = {PartitionsP[n], Sum[PartitionsP[n - j] DivisorSigma[0, j], {j, 1, n}]};
    b[n_, i_] := b[n, i] = If[i(i+1)/2 < n, 0, If[n == 0, {1, 0}, Module[{h, f}, h = g[i]; f = b[n - i, Min[n - i, i - 1]] h[[1]]; b[n, i - 1] + f + {0, f[[1]] h[[2]] / h[[1]]}]]];
    a[n_] := b[n, n][[2]];
    a /@ Range[0, 37] (* Jean-François Alcover, Dec 05 2020, after Alois P. Heinz *)

A327608 Number of parts in all twice partitions of n where the second partition is strict.

Original entry on oeis.org

0, 1, 3, 8, 17, 34, 74, 134, 254, 470, 842, 1463, 2620, 4416, 7545, 12749, 21244, 34913, 57868, 93583, 151963, 244602, 391206, 620888, 987344, 1550754, 2435087, 3804354, 5920225, 9162852, 14179754, 21785387, 33436490, 51121430, 77935525, 118384318, 179617794
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2019

Keywords

Examples

			a(3) = 8 = 1+2+2+3 counting the parts in 3, 21, 2|1, 1|1|1.
		

Crossrefs

Programs

  • Maple
    g:= proc(n, i) option remember; `if`(i*(i+1)/2 f+
           [0, f[1]])(g(n-i, min(n-i, i-1)))))
        end:
    b:= proc(n, i) option remember; `if`(n=0, [1, 0],
          `if`(i<2, 0, b(n, i-1)) +(h-> (f-> f +[0, f[1]*
           h[2]/h[1]])(b(n-i, min(n-i, i))*h[1]))(g(i$2)))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=0..37);
  • Mathematica
    g[n_, i_] := g[n, i] = If[i(i+1)/2 < n, 0, If[n == 0, {1, 0}, g[n, i - 1] + Function[f, f + {0, f[[1]]}][g[n - i, Min[n - i, i - 1]]]]];
    b[n_, i_] := b[n, i] = If[n == 0, {1, 0}, If[i < 2, 0, b[n, i - 1]] + Module[{h, f}, h = g[i, i]; f = b[n - i, Min[n - i, i]] h[[1]]; f + {0, f[[1]] h[[2]]/h[[1]]}]];
    a[n_] := b[n, n][[2]];
    a /@ Range[0, 37] (* Jean-François Alcover, Dec 05 2020, after Alois P. Heinz *)

A327590 Number of partitions in all twice partitions of n.

Original entry on oeis.org

0, 1, 4, 10, 29, 63, 164, 339, 797, 1640, 3578, 7139, 15210, 29621, 60381, 117116, 232523, 442388, 863069, 1621560, 3105993, 5785525, 10894394, 20083143, 37434186, 68344449, 125774280, 228088127, 415668548, 747660318, 1351364816, 2413792653, 4327245170
Offset: 0

Views

Author

Alois P. Heinz, Sep 17 2019

Keywords

Examples

			a(3) = 10 = 1+1+1+2+2+3 counting the partitions in 3, 21, 111, 2|1, 11|1, 1|1|1.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, [1, 0], `if`(i<1, 0, b(n, i-1)+
          (p-> p+[0, p[1]])(combinat[numbpart](i)*b(n-i, min(n-i, i)))))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=0..42);
  • Mathematica
    b[n_, i_] := b[n, i] = If[n == 0, {1, 0}, If[i<1, {0, 0}, b[n, i-1] + Function[p, p + {0, p[[1]]}][PartitionsP[i] b[n-i, Min[n-i, i]]]]];
    a[n_] := b[n, n][[2]];
    a /@ Range[0, 42] (* Jean-François Alcover, Dec 16 2020, after Alois P. Heinz *)
Showing 1-5 of 5 results.