OFFSET
1,1
COMMENTS
Greedy summability is defined at A242293.
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..400
EXAMPLE
Let s(n) = n^3 = A000578(n). Then
a(1) = 6; s(6) = 216 = 125 + 64 + 27;
a(2) = 9; s(9) = 729 = 512 + 216 + 1;
a(3) = 13; s(13) = 2197 = 1728 + 343 + 125 + 1;
a(4) = 14; s(14) = 2744 = 2197 + 512 + 27 + 8.
MATHEMATICA
z = 200; s = Table[n^3, {n, 1, z}]; t = Table[{s[[n]], #, Total[#] == s[[n]]} &[DeleteCases[-Differences[FoldList[If[#1 - #2 >= 0, #1 - #2, #1] &, s[[n]], Reverse[Select[s, # < s[[n]] &]]]], 0]], {n, z}]
r[n_] := s[[n]] - Total[t[[n]][[2]]];
tr = Table[r[n], {n, 2, z}] (* A242293 *)
c = Table[Length[t[[n]][[2]]], {n, 2, z}] (* A242294 *)
f = 1 + Flatten[Position[tr, 0]] (* A242295 *)
f^3 (* A242296 *) (* Peter J. C. Moses, May 06 2014 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 10 2014
STATUS
approved