login
A014643
Triangular array starting with {1,1}; then i-th term in a row gives number of i's in next row.
4
1, 1, 1, 2, 1, 2, 2, 1, 2, 2, 3, 3, 1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 5, 1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11
OFFSET
1,4
COMMENTS
The row {2} could be safely prepended to this triangle. - Gus Wiseman, May 13 2018
LINKS
Alois P. Heinz, Rows n = 1..8, flattened
EXAMPLE
Triangle begins:
{1,1},
{1,2},
{1,2,2},
{1,2,2,3,3},
...
MAPLE
T:= proc(n) option remember; `if`(n=0, 2, (l->
seq(i$l[i], i=1..nops(l)))([T(n-1)]))
end:
seq(T(n), n=1..7); # Alois P. Heinz, May 17 2018
MATHEMATICA
NestList[Join@@Table[Table[i, {#[[i]]}], {i, Length[#]}]&, {2}, 8] (* Gus Wiseman, May 13 2018 *)
CROSSREFS
KEYWORD
tabf,nonn
EXTENSIONS
More terms from Patrick De Geest
STATUS
approved