A332702 Lexicographically earliest sequence of distinct positive terms such that the leftmost digit of a(n) and the leftmost digit of a(n) + a(n+1) are the same.

1, 9, 81, 2, 18, 82, 3, 27, 173, 4, 36, 264, 5, 45, 355, 6, 54, 446, 7, 63, 537, 8, 72, 628, 10, 90, 810, 11, 89, 711, 12, 88, 712, 13, 87, 713, 14, 86, 714, 15, 85, 715, 16, 84, 716, 17, 83, 717, 19, 91, 809, 20, 180, 820, 21, 179, 821, 22, 178, 822, 23, 177, 823, 24, 176, 824, 25, 175, 825, 26

Offset

1,2

Links

Carole Dubois, Table of n, a(n) for n = 1..1000

Example

a(1) + a(2) = 1 + 9 = 10 with 1 the leftmost digit of both 1 and 10;
a(2) + a(3) = 9 + 81 = 90 with 9 the leftmost digit of both 9 and 90;
a(3) + a(4) = 81 + 2 = 83 with 8 the leftmost digit of  both 81 and 83;
a(4) + a(5) = 2 + 18 = 20 with 2 the leftmost digit of both 2 and 20;
a(5) + a(6) = 18 + 82 = 100 with 1 the leftmost digit of both 18 and 100; etc.

Crossrefs

Sequence in context: A317052 A363420 A352386 * A117817 A328760 A228591

Adjacent sequences: A332699 A332700 A332701 * A332703 A332704 A332705

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, Feb 20 2020

Status

approved