A288946 Starting with a(1) = 1, a(n) = smallest nonnegative integer not yet in the sequence such that the first digit of a(n) is plus or minus one the last digit of a(n-1) plus or minus 1, with preference given +1 when possible. The digit 0 is not allowed.

1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 21, 22, 31, 23, 41, 24, 51, 25, 61, 26, 71, 27, 82, 32, 33, 42, 34, 52, 35, 62, 36, 72, 37, 83, 43, 44, 53, 45, 63, 46, 73, 47, 84, 54, 55, 64, 56, 74, 57, 85, 65, 66, 75, 67, 86, 76, 77, 87, 88, 91, 28, 92, 38, 93, 48, 94, 58, 95, 68, 96, 78, 97, 89, 811, 29, 812, 39, 813, 49

Offset

1,2

Comments

If a(n-1) ends in 9, a(n) must begin with 8 (i.e., a forced decrease by 1).

Links

Table of n, a(n) for n=1..79.

Example

9 is followed by 81 in the sequence since there is no larger digit and 8 has already been used.

Crossrefs

Cf. A288945.

Sequence in context: A341909 A024663 A272360 * A237346 A193757 A246605

Adjacent sequences: A288943 A288944 A288945 * A288947 A288948 A288949

Keyword

nonn,base

Author

Enrique Navarrete, Jun 19 2017

Status

approved