A183231 First of two complementary trees generated by the triangular numbers. The second tree is A183232.

1, 4, 3, 19, 7, 13, 6, 229, 25, 43, 11, 118, 18, 34, 10, 26794, 250, 376, 32, 1033, 52, 89, 16, 7258, 133, 208, 24, 664, 42, 76, 15, 359026204, 27025, 31876, 272, 71629, 403, 593, 40, 536128, 1078, 1483, 62, 4184, 102, 169, 22, 26357428

Offset: 1

Author

Clark Kimberling, Jan 02 2011

Keywords

• nonn
• tabf

Comments

Begin with the main tree A183079 generated by the triangular numbers:

......................1

......................2

.............3.................4

.........6.......5........10........7

.......21..9...15..8....55..14....28..11

Every n>2 is in the subtree from 3 or the subtree from 4.

Therefore, on subtracting 2 from all entries of those subtrees, we obtain complementary trees: A183231 and A183232.

Examples

			First three levels:
............1
.......4.........3
....19...7.....13..6
		

Crossrefs

Cf. A183079, A183232 (second tree), A183233.

Formula

See the formulas at A183079 and A183233.