OFFSET
1,3
COMMENTS
If n(n+1)/2 is a square triangular number then the n-th row contains first n natural numbers (e.g., the 8th row).
EXAMPLE
1; 1,3; 1,2,6; 1,2,3,10; 1,2,3,4,6; 1,2,3,4,5,10; 1,2,3,4,5,6,15; 1,2,3,4,5,6,...
MAPLE
seq(op([seq(i, i=1..n-1), (ceil(sqrt(n*(n+1)/2)))^2 - n*(n-1)/2]), n=1..15); # C. Ronaldo
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Amarnath Murthy, Mar 21 2003
EXTENSIONS
More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 19 2004
STATUS
approved