A079214 Catalan paths: numbers starting with 1 and ending with 0 where each digit is nonnegative and adjacent digits differ by 1.

10, 1010, 1210, 101010, 101210, 121010, 121210, 123210, 10101010, 10101210, 10121010, 10121210, 10123210, 12101010, 12101210, 12121010, 12121210, 12123210, 12321010, 12321210, 12323210, 12343210, 1010101010, 1010101210

Offset: 1

Author

Henry Bottomley, Jan 02 2003

Keywords

• base
• nonn

Comments

a(23713) cannot easily be written in decimal.

Examples

			Can be constructed from A063171 by (starting from a notional leading 0) adding 1 to previous digit of a(n) if next digit of A063171 is 1 and subtracting 1 if next digit is 0: e.g. A063171(3)=1100, so digits of a(3) are 0+1=1, 1+1=2, 2-1=1 and 1-1=0 giving a(3)=1210.
		

Crossrefs

Cf. A063171, A079215. a(n) has A000108(m) values with 2m digits.

Formula

a(n) =A079215(n)-(10^ceiling[log_10(A079215(n))]-1)/9.