A352391 Lexicographically earliest sequence of distinct positive integers such that the last digit of |a(n) - a(n+1)| is the n-th digit of the sequence.

1, 2, 4, 8, 16, 5, 11, 6, 7, 18, 12, 19, 20, 28, 17, 15, 14, 23, 21, 31, 9, 27, 26, 33, 22, 37, 36, 32, 10, 13, 25, 24, 47, 46, 55, 3, 30, 42, 48, 35, 38, 40, 52, 29, 56, 43, 49, 62, 50, 39, 59, 58, 45, 57, 72, 60, 64, 68, 41, 65, 71, 66, 51, 54, 67, 77, 53, 75, 61, 69, 82, 87, 34, 92, 78, 88, 63, 85, 73

Offset

1,2

Links

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

Example

|a(1) - a(2)| = |1 - 2| = 1 and the terminal 1 of 1 is the 1st digit of the sequence;
|a(2) - a(3)| = |2 - 4| = 2 and the terminal 2 of 2 is the 2nd digit of the sequence;
|a(3) - a(4)| = |4 - 8| = 4 and the terminal 4 of 4 is the 3rd digit of the sequence;
|a(4) - a(5)| = |8 - 16| = 8 and the terminal 8 of 8 is the 4th digit of the sequence;
|a(5) - a(6)| = |16 - 5| = 11 and the terminal 1 of 11 is the 5th digit of the sequence; etc.

Mathematica

a[1]=1; a[n_]:=a[n]=Block[{k=1}, While[MemberQ[s=Array[a, n-1], k]||Mod[Abs[a[n-1]-k], 10]!=Flatten[IntegerDigits/@s][[n-1]], k++]; k]; Array[a, 79] (* Giorgos Kalogeropoulos, May 09 2022 *)

Crossrefs

Cf. A352386, A352387, A352389, A352390.

Sequence in context: A070337 A269305 A225570 * A178170 A127824 A088975

Adjacent sequences: A352388 A352389 A352390 * A352392 A352393 A352394

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, Mar 14 2022

Status

approved