A289288 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 10. The digit 0 is not allowed.

1, 9, 11, 91, 92, 8, 2, 81, 93, 7, 3, 71, 94, 6, 4, 61, 95, 5, 51, 96, 41, 97, 31, 98, 21, 99, 12, 82, 83, 72, 84, 62, 85, 52, 86, 42, 87, 32, 88, 22, 89, 13, 73, 74, 63, 75, 53, 76, 43, 77, 33, 78, 23, 79, 14, 64, 65, 54, 66, 44, 67, 34, 68, 24, 69, 15, 55, 56, 45, 57, 35, 58, 25, 59, 16, 46, 47, 36, 48, 26, 49, 17, 37, 38, 27, 39, 18, 28, 29, 19, 111, 911, 912, 811, 913, 711, 914, 611, 915, 511, 916, 411, 917, 311, 918, 211, 919, 112, 812, 813, 712

Offset

1,2

Comments

Unlike the sequences in A289283 - A289287, this sequence is infinite and does not seem to follow central polygonal numbers.

Links

Table of n, a(n) for n=1..111.

Mathematica

Module[{a = {1}, k, d = 10}, 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, Infinity}], 2]; a] (* Michael De Vlieger, Jul 14 2017 *)

Crossrefs

Cf. A002061, A289283, A289284, A289285, A289286, A289287.

Sequence in context: A038301 A359925 A277998 * A137016 A053886 A137020

Adjacent sequences: A289285 A289286 A289287 * A289289 A289290 A289291

Keyword

nonn,base

Author

Enrique Navarrete, Jul 01 2017

Status

approved