A363420 Let D be the largest digit of a(n) + a(n+1). The successive Ds reproduce the successive digits of the sequence. By construction, we do not accept any zero in the sequence. This is the lexicographically earliest sequence of distinct terms > 0 with this property.

1, 9, 81, 2, 8, 4, 14, 26, 74, 66, 36, 24, 3, 11, 5, 21, 12, 34, 68, 46, 57, 43, 58, 47, 55, 45, 56, 64, 39, 65, 41, 7, 17, 19, 6, 31, 13, 18, 27, 51, 53, 22, 23, 28, 15, 35, 16, 44, 62, 42, 61, 29, 32, 73, 67, 33, 37, 63, 54, 946, 25, 38, 75, 925, 76, 127, 873

Offset

1,2

Links

Table of n, a(n) for n=1..67.

Eric Angelini, Échecs et Maths, Personal blog, bottom of page.

Example

The largest digit of the sum 1 + 9 = 10 is 1
the largest digit of the sum 9 + 81 = 90 is 9
the largest digit of the sum 81 + 2 = 83 is 8
the largest digit of the sum 2 + 8 = 10 is 1
the largest digit of the sum 8 + 4 = 12 is 2
the largest digit of the sum 4 + 14 = 18 is 8, etc.
We see that the last column reproduces the successive digits of the sequence.

Mathematica

a[1]=1; a[n_]:=a[n]=(k=1; While[Max[s=IntegerDigits[k+a[n-1]]] !=Flatten[IntegerDigits/@Array[a, n-1]][[n-1]] ||MemberQ[IntegerDigits[k], 0] ||MemberQ[Array[a, n-1], k], k++]; k); Array[a, 67] (* Giorgos Kalogeropoulos, Jul 11 2023 *)

Crossrefs

Cf. A332803.

Sequence in context: A055070 A143848 A317052 * A352386 A332702 A117817

Adjacent sequences: A363417 A363418 A363419 * A363421 A363422 A363423

Keyword

base,nonn

Author

Eric Angelini, Jul 03 2023

Status

approved