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A344450
Lexicographically earliest sequence S of distinct nonnegative terms such that the n-th even digit of S is present in a(n).
0
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 30, 40, 24, 50, 21, 34, 60, 22, 41, 26, 70, 23, 25, 42, 27, 36, 80, 28, 29, 43, 32, 52, 46, 38, 90, 62, 48, 72, 44, 82, 92, 45, 56, 58, 100, 61, 102, 47, 68, 112, 49, 54, 78, 120, 121, 64, 63, 81, 101, 103, 65, 104, 122, 74, 66, 83, 123, 84, 94, 85, 124, 105, 125, 67
OFFSET
1,2
EXAMPLE
The 14th even digit of S is 4 (from 40) and this 4 is present in the 14th term of S (which is 24).
MATHEMATICA
a[1]=0; a[n_]:=a[n]=Block[{k=1}, While[MemberQ[l=Array[a, n-1], k]||FreeQ[IntegerDigits@k, Quiet@Select[Flatten[IntegerDigits/@Join[l, {k}]], EvenQ][[n]]], k++]; k]; Array[a, 75] (* Giorgos Kalogeropoulos, May 11 2022 *)
CROSSREFS
Cf. A247143.
Sequence in context: A134930 A084562 A344453 * A240714 A276463 A187350
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Carole Dubois, May 19 2021
STATUS
approved