A352389 Lexicographically earliest sequence of distinct positive integers such that the first digit of a(n)*a(n+1) is the n-th digit of the sequence (integers including a zero are excluded).

1, 11, 12, 9, 2, 13, 7, 3, 4, 8, 88, 35, 14, 6, 134, 61, 5, 111, 15, 27, 23, 44, 69, 58, 112, 16, 32, 33, 31, 34, 36, 139, 17, 42, 48, 63, 64, 65, 93, 97, 52, 154, 66, 18, 113, 89, 68, 45, 46, 67, 47, 71, 19, 21, 22, 137, 49, 24, 125, 72, 25, 28, 143, 141, 29, 276, 218, 138, 435, 92, 73, 74, 122, 26, 37, 191

Offset

1,2

Links

Table of n, a(n) for n=1..76.

Example

a(1) * a(2) =  1 * 11 =  11 and the initial 1 of  11 is the 1st digit of the sequence;
a(2) * a(3) = 11 * 12 = 132 and the initial 1 of 132 is the 2nd digit of the sequence;
a(3) * a(4) = 12 *  9 = 108 and the initial 1 of 108 is the 3rd digit of the sequence;
a(4) * a(5) =  9 *  2 =  18 and the initial 1 of  16 is the 4th digit of the sequence;
a(5) * a(6) =  2 * 13 =  26 and the initial 2 of  26 is the 5th digit of the sequence; etc.

Crossrefs

Cf. A352386, A352387.

Sequence in context: A329127 A076654 A264811 * A020510 A291521 A324309

Adjacent sequences: A352386 A352387 A352388 * A352390 A352391 A352392

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, Mar 14 2022

Status

approved