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 12 results. Next

A116646 Number of doubletons in all partitions of n. By a doubleton in a partition we mean an occurrence of a part exactly twice (the partition [4,(3,3),2,2,2,(1,1)] has two doubletons, shown between parentheses).

Original entry on oeis.org

0, 0, 1, 0, 2, 2, 4, 5, 10, 11, 20, 25, 38, 49, 73, 91, 131, 167, 228, 291, 392, 493, 653, 822, 1065, 1336, 1714, 2131, 2706, 3354, 4209, 5193, 6471, 7934, 9817, 11990, 14725, 17909, 21875, 26477, 32172, 38797, 46893, 56339, 67804, 81147, 97260, 116017
Offset: 0

Views

Author

Emeric Deutsch, Feb 20 2006

Keywords

Comments

a(n) = (the number of 2's in all partitions of n) - (the number of 3's in all partitions of n). - Gregory L. Simay, Jul 28 2020

Examples

			a(6) = 4 because in the partitions of 6, namely [6],[5,1],[4,2],[4,(1,1)],[(3,3)],[3,2,1],[3,1,1,1],[2,2,2],[(2,2),(1,1)],[2,1,1,1,1] and [1,1,1,1,1,1], we have a total of 4 doubletons (shown between parentheses).
		

Crossrefs

Cf. A116644. Column k=2 of A197126.

Programs

  • Maple
    f:= x^2/(1+x)/(1-x^3)/product(1-x^j, j=1..70): fser:= series(f,x=0,70): seq(coeff(fser,x,n), n=0..55);
  • Mathematica
    nmax = 50; CoefficientList[Series[x^2/((1+x)*(1-x^3)) * Product[1/(1-x^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Mar 07 2016 *)
    Table[Sum[PartitionsP[n-6*m-2] - PartitionsP[n-6*m-3] + PartitionsP[n-6*m-4], {m, 0, Floor[n/6]}], {n, 0, 50}] (* Vaclav Kotesovec, Mar 07 2016 *)

Formula

G.f.: x^2 / ((1+x)*(1-x^3)*(Product_{j>=1} 1-x^j)).
a(n) = Sum_{k>=0} k * A116644(n,k).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (3*2^(5/2)*Pi*sqrt(n)). - Vaclav Kotesovec, Mar 07 2016

A117524 Total number of parts of multiplicity 3 in all partitions of n.

Original entry on oeis.org

0, 0, 1, 0, 1, 2, 3, 3, 7, 8, 13, 17, 25, 32, 48, 59, 83, 108, 145, 183, 247, 310, 406, 512, 659, 824, 1055, 1307, 1651, 2047, 2558, 3146, 3913, 4788, 5904, 7202, 8821, 10707, 13054, 15770, 19118, 23027, 27775, 33312, 40029, 47835, 57231, 68182, 81261
Offset: 1

Views

Author

Vladeta Jovovic, Apr 26 2006

Keywords

Examples

			a(9) = 7 because among the 30 (=A000041(9)) partitions of 9 only [6,(1,1,1)],[4,2,(1,1,1)],[(3,3,3)],[3,3,(1,1,1)],[3,(2,2,2)],[(2,2,2),(1,1,1)] contain parts of multiplicity 3 and their total number is 7 (shown between parentheses)
		

Crossrefs

Cf. A024786, A116646. Column k=3 of A197126.

Programs

  • Maple
    g:=(x^3/(1-x^3)-x^4/(1-x^4))/product(1-x^i,i=1..65): gser:=series(g,x=0,62): seq(coeff(gser,x,n),n=1..58); # Emeric Deutsch, Apr 29 2006

Formula

G.f. for total number of parts of multiplicity m in all partitions of n is (x^m/(1-x^m)-x^(m+1)/(1-x^(m+1)))/Product(1-x^i,i=1..infinity).
a(n) = Sum(k*A118806(n,k), k>=0). - Emeric Deutsch, Apr 29 2006
a(n) ~ exp(Pi*sqrt(2*n/3)) / (24*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018

A299779 Triangle read by rows: T(n,k) is the total number of cliques of size k in all partitions of all positive integers <= n.

Original entry on oeis.org

1, 2, 1, 5, 1, 1, 9, 3, 1, 1, 17, 5, 2, 1, 1, 28, 9, 4, 2, 1, 1, 47, 14, 7, 3, 2, 1, 1, 73, 24, 10, 6, 3, 2, 1, 1, 114, 35, 17, 9, 5, 3, 2, 1, 1, 170, 55, 25, 14, 8, 5, 3, 2, 1, 1, 253, 80, 38, 20, 13, 7, 5, 3, 2, 1, 1, 365, 118, 55, 31, 18, 12, 7, 5, 3, 2, 1, 1, 525, 167, 80, 44, 27, 17, 11, 7, 5, 3, 2, 1, 1
Offset: 1

Views

Author

Omar E. Pol, Apr 04 2018

Keywords

Comments

Column k gives the partial sums of the k-th column of triangle A197126.

Examples

			Triangle begins:
    1;
    2,   1;
    5,   1,  1;
    9,   3,  1,  1;
   17,   5,  2,  1,  1;
   28,   9,  4,  2,  1,  1;
   47,  14,  7,  3,  2,  1,  1;
   73,  24, 10,  6,  3,  2,  1,  1;
  114,  35, 17,  9,  5,  3,  2,  1,  1;
  170,  55, 25, 14,  8,  5,  3,  2,  1,  1;
  253,  80, 38, 20, 13,  7,  5,  3,  2,  1,  1;
  365, 118, 55, 31, 18, 12,  7,  5,  3,  2,  1,  1;
  525, 167, 80, 44, 27, 17, 11,  7,  5,  3,  2,  1,  1;
...
		

Crossrefs

Column 1 gives A000097.
Row sums give A014153.

Programs

  • Maple
    b:= proc(n, p, k) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=k, l+[0, l[1]], l))(b(n-p*m, p-1, k)), m=0..n/p)))
        end:
    T:= proc(n, k) option remember;
          b(n$2, k)[2]+`if`(nAlois P. Heinz, Apr 27 2018
  • Mathematica
    b[n_, p_, k_] := b[n, p, k] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[ Function[l, If[m==k, l+{0, l[[1]]}, l]][b[n-p*m, p-1, k]], {m, 0, n/p}]]];
    T[n_, k_] := b[n, n, k][[2]] + If[n < k, 0, T[n-1, k]];
    Table[Table[T[n, k], {k, 1, n}], {n, 1, 20}] // Flatten (* Jean-François Alcover, Dec 07 2019, after Alois P. Heinz *)

Formula

T(n,k) = Sum_{j=k..n} A197126(j,k).
T(2n+1,n+1) = A000041(n). - Alois P. Heinz, Apr 27 2018
Sum_{k=1..n} k * T(n,k) = A284870(n). - Alois P. Heinz, May 14 2018

A213180 Sum over all partitions lambda of n of Sum_{p:lambda} p^m(p,lambda), where m(p,lambda) is the multiplicity of part p in lambda.

Original entry on oeis.org

0, 1, 3, 7, 16, 28, 59, 91, 170, 269, 450, 655, 1162, 1602, 2527, 3793, 5805, 8034, 12660, 17131, 26484, 37384, 53738, 73504, 114683, 153613, 221225, 313339, 453769, 609179, 927968, 1223909, 1804710, 2522264, 3539835, 4855420, 7439870, 9765555, 14009545
Offset: 0

Views

Author

Alois P. Heinz, Feb 27 2013

Keywords

Examples

			a(6) = 59: (1^6) + (2+1^4) + (2^2+1^2) + (2^3) + (3+1^3) + (3+2+1) + (3^2) + (4+1^2) + (4+2) + (5+1) + (6) = 1+3+5+8+4+6+9+5+6+6+6 = 59.
		

Crossrefs

Cf. A000070 (Sum 1), A006128 (Sum m), A014153 (Sum p), A024786 (Sum floor(1/m)), A066183 (Sum p^2*m), A066186 (Sum p*m), A073336 (Sum floor(m/p)), A116646 (Sum delta(m,2)), A117524 (Sum delta(m,3)), A103628 (Sum delta(m,1)*p), A117525 (Sum delta(m,2)*p), A197126, A213191.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=0, l, l+[0, l[1]*p^m]))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=0..40);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n==0, {1, 0}, If[p<1, {0, 0}, Sum[Function[l, If[m==0, l, l+{0, l[[1]]*p^m}]][b[n-p*m, p-1]], {m, 0, n/p}]]]; a[n_] := b[n, n][[2]]; Table[a[n], {n, 0, 40}] (* Jean-François Alcover, Feb 15 2017, translated from Maple *)

Formula

From Vaclav Kotesovec, May 24 2018: (Start)
a(n) ~ c * 3^(n/3), where
c = 5.0144820680945600131204662934686439430547... if mod(n,3)=0
c = 4.6144523178014379613985400559486878971522... if mod(n,3)=1
c = 4.5237761454818383598444208605033385016299... if mod(n,3)=2
(End)

A222704 Total number of parts of multiplicity 4 in all partitions of n.

Original entry on oeis.org

1, 0, 1, 1, 3, 3, 5, 6, 11, 13, 20, 24, 37, 45, 64, 80, 110, 137, 184, 229, 303, 375, 486, 602, 772, 951, 1202, 1478, 1853, 2267, 2817, 3432, 4236, 5142, 6300, 7620, 9284, 11185, 13553, 16273, 19625, 23478, 28187, 33613, 40192, 47778, 56904, 67443, 80051
Offset: 4

Views

Author

Alois P. Heinz, Feb 28 2013

Keywords

Crossrefs

Column k=4 of A197126.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=4, l+[0, l[1]], l))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=4..60);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n == 0, {1, 0}, If[p<1, {0, 0}, Sum[Function[l, If[m == 4, l + {0, l[[1]]}, l]][b[n - p*m, p - 1]], {m, 0, n/p}]]];
    a[n_] := b[n, n][[2]];
    Table[a[n], {n, 4, 60}] (* Jean-François Alcover, Apr 30 2018, after Alois P. Heinz *)

Formula

G.f.: (x^4/(1-x^4)-x^5/(1-x^5))/Product_{j>0}(1-x^j).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (40*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018

A222705 Total number of parts of multiplicity 5 in all partitions of n.

Original entry on oeis.org

1, 0, 1, 1, 2, 3, 5, 5, 9, 11, 17, 21, 31, 37, 53, 67, 90, 113, 151, 186, 246, 305, 392, 486, 620, 762, 962, 1181, 1473, 1802, 2235, 2716, 3345, 4056, 4956, 5990, 7283, 8759, 10598, 12709, 15297, 18283, 21917, 26099, 31165, 37009, 44014, 52113, 61776, 72918
Offset: 5

Views

Author

Alois P. Heinz, Feb 28 2013

Keywords

Crossrefs

Column k=5 of A197126.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=5, l+[0, l[1]], l))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=5..60);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[Function[l, If[m == 5, l + {0, l[[1]]}, l]][b[n - p*m, p - 1]], {m, 0, n/p}]]];
    a[n_] := b[n, n][[2]];
    Table[a[n], {n, 5, 60}] (* Jean-François Alcover, Apr 30 2018, after Alois P. Heinz *)

Formula

G.f.: (x^5/(1-x^5)-x^6/(1-x^6))/Product_{j>0}(1-x^j).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (60*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018

A222706 Total number of parts of multiplicity 6 in all partitions of n.

Original entry on oeis.org

1, 0, 1, 1, 2, 2, 5, 5, 8, 10, 15, 18, 28, 33, 47, 58, 79, 97, 132, 161, 212, 262, 337, 414, 531, 648, 818, 1001, 1249, 1519, 1887, 2285, 2812, 3401, 4155, 5004, 6086, 7301, 8827, 10565, 12708, 15155, 18162, 21587, 25757, 30539, 36296, 42904, 50832, 59915
Offset: 6

Views

Author

Alois P. Heinz, Feb 28 2013

Keywords

Crossrefs

Column k=6 of A197126.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=6, l+[0, l[1]], l))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=6..60);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[Function[l, If[m == 6, l + {0, l[[1]]}, l]][b[n - p*m, p - 1]], {m, 0, n/p}]]];
    a[n_] := b[n, n][[2]];
    Table[a[n], {n, 6, 60}] (* Jean-François Alcover, Apr 30 2018, after Alois P. Heinz *)

Formula

G.f.: (x^6/(1-x^6)-x^7/(1-x^7))/Product_{j>0}(1-x^j).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (84*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018

A222707 Total number of parts of multiplicity 7 in all partitions of n.

Original entry on oeis.org

1, 0, 1, 1, 2, 2, 4, 5, 8, 9, 14, 17, 25, 30, 43, 53, 72, 88, 118, 145, 190, 234, 301, 370, 471, 575, 724, 884, 1102, 1339, 1657, 2007, 2465, 2975, 3630, 4369, 5301, 6355, 7672, 9171, 11018, 13126, 15706, 18655, 22231, 26329, 31260, 36920, 43688, 51454, 60693
Offset: 7

Views

Author

Alois P. Heinz, Feb 28 2013

Keywords

Crossrefs

Column k=7 of A197126.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=7, l+[0, l[1]], l))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=7..60);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[Function[l, If[m == 7, l + {0, l[[1]]}, l]][b[n - p*m, p - 1]], {m, 0, n/p}]]];
    a[n_] := b[n, n][[2]];
    Table[a[n], {n, 7, 60}] (* Jean-François Alcover, Apr 30 2018, after Alois P. Heinz *)

Formula

G.f.: (x^7/(1-x^7)-x^8/(1-x^8))/Product_{j>0}(1-x^j).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (112*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018

A222708 Total number of parts of multiplicity 8 in all partitions of n.

Original entry on oeis.org

1, 0, 1, 1, 2, 2, 4, 4, 8, 9, 13, 16, 24, 28, 40, 49, 67, 82, 110, 133, 176, 215, 276, 338, 432, 524, 661, 804, 1001, 1214, 1502, 1812, 2228, 2683, 3270, 3928, 4766, 5699, 6879, 8208, 9855, 11724, 14020, 16624, 19804, 23423, 27788, 32781, 38770, 45603, 53762
Offset: 8

Views

Author

Alois P. Heinz, Feb 28 2013

Keywords

Crossrefs

Column k=8 of A197126.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=8, l+[0, l[1]], l))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=8..60);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[Function[l, If[m == 8, l + {0, l[[1]]}, l]][b[n - p*m, p - 1]], {m, 0, n/p}]]];
    a[n_] := b[n, n][[2]];
    Table[a[n], {n, 8, 60}] (* Jean-François Alcover, Apr 30 2018, after Alois P. Heinz *)

Formula

G.f.: (x^8/(1-x^8)-x^9/(1-x^9))/Product_{j>0}(1-x^j).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (144*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018

A222709 Total number of parts of multiplicity 9 in all partitions of n.

Original entry on oeis.org

1, 0, 1, 1, 2, 2, 4, 4, 7, 9, 13, 15, 23, 27, 38, 47, 63, 77, 104, 126, 165, 202, 259, 316, 403, 489, 614, 748, 929, 1125, 1391, 1676, 2055, 2475, 3012, 3613, 4379, 5233, 6306, 7521, 9018, 10717, 12805, 15171, 18050, 21337, 25288, 29806, 35221, 41400, 48760
Offset: 9

Views

Author

Alois P. Heinz, Feb 28 2013

Keywords

Crossrefs

Column k=9 of A197126.

Programs

  • Maple
    b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
          add((l->`if`(m=9, l+[0, l[1]], l))(b(n-p*m, p-1)), m=0..n/p)))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=9..60);
  • Mathematica
    b[n_, p_] := b[n, p] = If[n == 0, {1, 0}, If[p < 1, {0, 0}, Sum[Function[l, If[m == 9, l + {0, l[[1]]}, l]][b[n - p*m, p - 1]], {m, 0, n/p}]]];
    a[n_] := b[n, n][[2]];
    Table[a[n], {n, 9, 60}] (* Jean-François Alcover, Apr 30 2018, after Alois P. Heinz *)

Formula

G.f.: (x^9/(1-x^9)-x^10/(1-x^10))/Product_{j>0}(1-x^j).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (180*Pi*sqrt(2*n)). - Vaclav Kotesovec, May 24 2018
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