A289286 Starting with a(1) = 1, a(n) = smallest nonnegative integer not yet in the sequence such that the last digit of a(n-1) plus the first digit of a(n) is equal to 8. The digit 0 is not allowed.

1, 7, 11, 71, 72, 6, 2, 61, 73, 5, 3, 51, 74, 4, 41, 75, 31, 76, 21, 77, 12, 62, 63, 52, 64, 42, 65, 32, 66, 22, 67, 13, 53, 54, 43, 55, 33, 56, 23, 57, 14, 44, 45, 34, 46, 24, 47, 15, 35, 36, 25, 37, 16, 26, 27, 17, 18

Offset

1,2

Comments

The number of terms of this finite sequence is the eighth central polygonal number, n = 57.

Links

Table of n, a(n) for n=1..57.

Mathematica

Module[{a = {1}, k, d = 8}, TimeConstrained[Do[k = 2; While[Or[MemberQ[a, k], MemberQ[IntegerDigits@ k, 0], # != d] &[Mod[a[[n - 1]], 10] + First@ IntegerDigits@ k], k++]; AppendTo[a, k], {n, 2, 100}], 2]; a] (* Michael De Vlieger, Jul 14 2017 *)

Crossrefs

Cf. A002061, A289283, A289284, A289285.

Sequence in context: A196181 A177182 A061809 * A337099 A123763 A018680

Adjacent sequences: A289283 A289284 A289285 * A289287 A289288 A289289

Keyword

nonn,base,fini,full

Author

Enrique Navarrete, Jul 01 2017

Status

approved