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

1,1

Comments

a(23713) cannot easily be written in decimal.

Links

Table of n, a(n) for n=1..24.

Formula

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

Example

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.

Sequence in context: A071671 A075171 A106456 * A163662 A176067 A080070

Adjacent sequences: A079211 A079212 A079213 * A079215 A079216 A079217

Keyword

base,nonn

Author

Henry Bottomley, Jan 02 2003

Status

approved