OFFSET
0,2
COMMENTS
Two possibilities of triangle on line. 1) From 1: 1; 3, 5; 6, 10, 11; 12, 20, 21, 22; 24, 40, 42, 43, 44; . 2) After 1: 3; 5, 6; 10, 11, 12; 20, 21, 22, 24; .
FORMULA
CROSSREFS
KEYWORD
nonn,uned
AUTHOR
Paul Curtz, Jul 25 2008
STATUS
approved