A182094 Total area of the bounding boxes of all integer partitions of n.

0, 1, 4, 10, 24, 47, 93, 162, 283, 462, 747, 1154, 1779, 2642, 3908, 5643, 8098, 11398, 15975, 22030, 30253, 41027, 55379, 73983, 98455, 129838, 170578, 222447, 289009, 373064, 479970, 613962, 782893, 993349, 1256546, 1582466, 1987365, 2485840, 3101146

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Formula

a(n) = A188814(n) + n*A000041(n) = A188814(n) + A066186(n).

Example

a(4) = 24 = 4+6+4+6+4 because the partitions of 4 are [1,1,1,1], [1,1,2], [2,2], [1,3], [4] and the bounding boxes have areas 4*1, 3*2, 2*2, 2*3, 1*4.
a(5) = 47 = 5+8+6+9+6+8+5 because the partitions of 5 are [1,1,1,1,1], [1,1,1,2], [1,2,2], [1,1,3], [2,3], [1,4], [5].

Maple

b:= proc(n, i) option remember; local f, g;
      if n=0 or i=1 then [1, n]
    elif i<1 then [0, 0]
    else f:= b(n, i-1); g:= `if`(i>n, [0, 0], b(n-i, i));
         [f[1]+g[1], f[2]+g[2]+g[1]]
      fi
    end:
a:= n-> add(add(i, i=b(n-j, min(j, n-j)))*j, j=1..n):
seq(a(n), n=0..40);

Mathematica

b[n_, i_] := b[n, i] = Module[{f, g}, If[n == 0 || i == 1, {1, n}, If[i < 1, {0, 0}, f = b[n, i - 1]; g = If[i > n, {0, 0}, b[n - i, i]]]; {f[[1]] + g[[1]], f[[2]] + g[[2]] + g[[1]]}]]; a[n_] := Sum[Sum[i, {i, b[n - j, Min[j, n - j]]}]*j, {j, 1, n}]; Table[a[n], {n, 0, 40}] (* Jean-François Alcover, Feb 05 2017, translated from Maple *)

Crossrefs

Cf. A000041, A066186, A115995, A188814.

Sequence in context: A083168 A143696 A058514 * A291949 A001979 A209970

Adjacent sequences: A182091 A182092 A182093 * A182095 A182096 A182097

Keyword

nonn

Author

Alois P. Heinz, Apr 11 2012

Status

approved