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

Author

Alois P. Heinz, Apr 11 2012

Keywords

• nonn

Examples

			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].
		

Links

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

Crossrefs

Cf. A000041, A066186, A115995, A188814.

Programs

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 *)

Formula

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