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.

A222044 Sum of smallest parts of all partitions of n into an odd number of parts.

Original entry on oeis.org

0, 1, 2, 4, 5, 8, 11, 15, 19, 28, 35, 47, 61, 80, 102, 136, 168, 218, 276, 350, 437, 556, 686, 860, 1063, 1321, 1620, 2005, 2443, 2998, 3649, 4445, 5377, 6531, 7863, 9496, 11398, 13694, 16373, 19603, 23347, 27834, 33058, 39259, 46467, 55020, 64914, 76599
Offset: 0

Views

Author

Alois P. Heinz, Feb 06 2013

Keywords

Comments

a(n) + A222045(n) = A046746(n).
a(n) - A222045(n) = A222046(n).

Examples

			a(6) = 11: partitions of 6 into an odd number of parts are [2,1,1,1,1], [2,2,2], [3,2,1], [4,1,1], [6], sum of smallest parts is 1+2+1+1+6 = 11.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember;
          [`if`(n=i, n, 0), 0]+`if`(i<1, [0, 0], b(n, i-1)+
           `if`(n [l[2], l[1]])(b(n-i, i))))
        end:
    a:= n-> b(n, n)[1]:
    seq(a(n), n=0..60);
  • Mathematica
    b[n_, i_] := b[n, i] = {If[n==i, n, 0], 0} + If[i<1, {0, 0}, b[n, i-1] + If[nJean-François Alcover, Feb 03 2017, translated from Maple *)
    Table[Total[Min/@Select[IntegerPartitions[n],OddQ[Length[#]]&]],{n,0,50}] (* Harvey P. Dale, Jul 05 2019 *)

Formula

a(n) ~ exp(Pi*sqrt(2*n/3)) / (8*sqrt(3)*n). - Vaclav Kotesovec, Jul 06 2019

A222045 Sum of smallest parts of all partitions of n into an even number of parts.

Original entry on oeis.org

0, 0, 1, 1, 4, 4, 9, 10, 19, 21, 34, 40, 62, 72, 103, 124, 173, 207, 279, 337, 445, 538, 694, 842, 1077, 1299, 1634, 1977, 2464, 2969, 3669, 4411, 5410, 6488, 7896, 9447, 11442, 13640, 16421, 19536, 23411, 27761, 33124, 39174, 46554, 54915, 65008, 76485, 90258
Offset: 0

Views

Author

Alois P. Heinz, Feb 06 2013

Keywords

Comments

A222044(n) + a(n) = A046746(n).
A222044(n) - a(n) = A222046(n).

Examples

			a(6) = 9: partitions of 6 into an even number of parts are [1,1,1,1,1,1], [2,2,1,1], [3,1,1,1], [3,3], [4,2], [5,1], sum of smallest parts is 1+1+1+3+2+1 = 9.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember;
          [`if`(n=i, n, 0), 0]+`if`(i<1, [0, 0], b(n, i-1)+
           `if`(n [l[2], l[1]])(b(n-i, i))))
        end:
    a:= n-> b(n, n)[2]:
    seq(a(n), n=0..60);
  • Mathematica
    b[n_, i_] := b[n, i] = {If[n==i, n, 0], 0} + If[i<1, {0, 0}, b[n, i-1] + If[nJean-François Alcover, Feb 03 2017, translated from Maple *)

Formula

a(n) ~ exp(Pi*sqrt(2*n/3)) / (8*sqrt(3)*n). - Vaclav Kotesovec, Jul 06 2019

A222047 Sum of largest parts of all partitions of n into an odd number of parts.

Original entry on oeis.org

0, 1, 2, 4, 6, 11, 17, 28, 41, 66, 93, 140, 195, 282, 384, 541, 722, 992, 1311, 1762, 2299, 3045, 3929, 5127, 6559, 8458, 10726, 13689, 17225, 21780, 27224, 34134, 42387, 52769, 65138, 80544, 98887, 121538, 148456, 181456, 220590, 268252, 324677, 392961
Offset: 0

Views

Author

Alois P. Heinz, Feb 06 2013

Keywords

Comments

a(n) + A222048(n) = A006128(n).
a(n) - A222048(n) = A222049(n).

Examples

			a(6) = 17: partitions of 6 into an odd number of parts are [2,1,1,1,1], [2,2,2], [3,2,1], [4,1,1], [6], sum of largest parts is 2+2+3+4+6 = 17.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; [`if`(n=i, n, 0), 0]+
          `if`(i>n, [0, 0], b(n, i+1)+(l-> [l[2], l[1]])(b(n-i, i)))
        end:
    a:= n-> b(n,1)[1]:
    seq(a(n), n=0..50);
  • Mathematica
    Table[Total[Max[#]&/@Select[IntegerPartitions[n],OddQ[Length[#]]&]],{n,0,50}] (* Harvey P. Dale, Apr 19 2014 *)
    b[n_, i_] := b[n, i] = {If[n==i, n, 0], 0} + If[i>n, {0, 0}, b[n, i+1] + Reverse[b[n-i, i]]]; a[n_] := b[n, 1][[1]]; Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Aug 30 2016, after Alois P. Heinz *)

A222048 Sum of largest parts of all partitions of n into an even number of parts.

Original entry on oeis.org

0, 0, 1, 2, 6, 9, 18, 26, 45, 62, 99, 135, 204, 274, 396, 527, 741, 973, 1333, 1736, 2331, 3007, 3970, 5079, 6615, 8393, 10796, 13605, 17320, 21673, 27339, 34001, 42540, 52597, 65324, 80332, 99127, 121274, 148745, 181131, 220956, 267852, 325114, 392476, 474178
Offset: 0

Views

Author

Alois P. Heinz, Feb 06 2013

Keywords

Comments

A222047(n) + a(n) = A006128(n).
A222047(n) - a(n) = A222049(n).

Examples

			a(6) = 18: partitions of 6 into an even number of parts are [1,1,1,1,1,1], [2,2,1,1], [3,1,1,1], [3,3], [4,2], [5,1], sum of largest parts is 1+2+3+3+4+5 = 18.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; [`if`(n=i, n, 0), 0]+
          `if`(i>n, [0, 0], b(n, i+1)+(l-> [l[2], l[1]])(b(n-i, i)))
        end:
    a:= n-> b(n,1)[2]:
    seq(a(n), n=0..50);
  • Mathematica
    b[n_, i_] := b[n, i] = {If[n==i, n, 0], 0} + If[i>n, {0, 0}, b[n, i+1] + Reverse @ b[n-i, i]]; a[n_] := b[n, 1][[2]]; Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Feb 02 2017, translated from Maple *)

A222049 Difference between sums of largest parts of all partitions of n into odd number of parts and into even number of parts.

Original entry on oeis.org

0, 1, 1, 2, 0, 2, -1, 2, -4, 4, -6, 5, -9, 8, -12, 14, -19, 19, -22, 26, -32, 38, -41, 48, -56, 65, -70, 84, -95, 107, -115, 133, -153, 172, -186, 212, -240, 264, -289, 325, -366, 400, -437, 485, -544, 597, -649, 714, -799, 869, -942, 1037, -1148, 1246, -1351
Offset: 0

Views

Author

Alois P. Heinz, Feb 06 2013

Keywords

Examples

			a(6) = -1 = (2+2+3+4+6) - (1+2+3+3+4+5) because the partitions of 6 into an odd number of parts are [2,1,1,1,1], [2,2,2], [3,2,1], [4,1,1], [6] and the partitions of 6 into an even number of parts are [1,1,1,1,1,1], [2,2,1,1], [3,1,1,1], [3,3], [4,2], [5,1].
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; [`if`(n=i, n, 0), 0]+
          `if`(i>n, [0, 0], b(n, i+1)+(l-> [l[2], l[1]])(b(n-i, i)))
        end:
    a:= n-> (l->l[1]-l[2])(b(n, 1)):
    seq(a(n), n=0..60);
  • Mathematica
    b[n_, i_] := b[n, i] = {If[n==i, n, 0], 0} + If[i>n, {0, 0}, b[n, i+1] + Reverse @ b[n-i, i]]; a[n_] :=  b[n, 1][[1]]-b[n, 1][[2]]; Table[a[n], {n, 0, 60}] (* Jean-François Alcover, Feb 02 2017, translated from Maple *)

Formula

a(n) = A222047(n) - A222048(n).
G.f.: Sum_{i>=0} i*x^i/Product_{j=1..i} (1 + x^j). - Ilya Gutkovskiy, Apr 13 2018
Showing 1-5 of 5 results.