A084390 a(n) is the smallest positive integer > a(n-1) with exactly n letters when spelled in English.

1, 4, 7, 11, 15, 18, 21, 24, 27, 73, 101, 104, 107, 111, 115, 118, 121, 124, 127, 173, 323, 373, 1104, 1107, 1111, 1115, 1118, 1121, 1124, 1127, 1173, 1323, 1373, 3323, 3373, 11373, 13323, 13373, 17373, 23323, 23373, 73373, 101373, 103323, 103373, 111373

Offset: 3

Author

James Ong (blackshadowshade(AT)yahoo.com.au), Jun 27 2003

Keywords

• easy
• nonn
• word
• fini

Comments

This uses the conventions that "and" is never used and two-digit numbers are not used before "hundred". The sequence is labeled "finite" because there is no widely accepted naming convention for arbitrarily large numbers. - David Wasserman, Dec 20 2004

Examples

			a(5) = 7 because 'seven' has 5 letters.
		

Links

• Andrew Bolt et al., Maths fun, rec.puzzles group.
• jaysmith et al., Number sequence - spot the pattern, rec.puzzles group.
• Wikipedia, English numerals

Crossrefs

Cf. A080777.

Extensions

More terms from David Wasserman, Dec 20 2004