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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
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
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
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Carole Dubois, Feb 20 2020
STATUS
approved