A072039 Row of Zorach additive triangle in which n appears (or 0 in the unlikely event that it does not).

1, 2, 2, 3, 5, 3, 4, 6, 3, 7, 4, 5, 6, 8, 9, 11, 4, 7, 10, 12, 13, 14, 5, 8, 6, 4, 15, 17, 9, 16, 7, 19, 18, 10, 11, 12, 21, 20, 22, 5, 13, 8, 14, 23, 24, 26, 27, 6, 15, 35, 25, 30, 9, 28, 29, 7, 16, 17, 31, 33, 18, 32, 10, 34, 19, 5, 36, 40, 11, 20, 12, 37, 8, 39, 21, 22, 13, 38, 45, 43

Offset: 1

Author

Henry Bottomley, Jun 07 2002

Keywords

• nonn

Examples

			a(8)=6 since 8 appears in the sixth row.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
• A. C. Zorach, Additive triangle
• Haskell programs for sequences in connection with Zorach additive triangle

Crossrefs

Cf. A035312, A035311, A035313, A035358, A072038.

Programs

Haskell

-- See link.

Formula

If a(n) > 0: n = A035312(a(n)-1, A072038(n)-1).