A333404 Lexicographically earliest sequence of positive distinct integers such that if a(n) steps over a(n) commas to the right, it is met by a term whose leftmost digit is prime.

1, 2, 3, 5, 4, 7, 6, 8, 20, 9, 10, 11, 21, 12, 13, 22, 14, 15, 23, 16, 24, 17, 25, 18, 19, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 50, 42, 51, 52, 43, 44, 53, 45, 46, 47, 54, 48, 55, 49, 56, 57, 58, 59, 70, 60, 71, 61, 72, 62, 73, 63, 74, 64, 75, 65, 76, 66, 77, 67, 78, 68, 79, 69, 200, 80

Offset

1,2

Links

Carole Dubois, Table of n, a(n) for n = 1..5000

Example

a(1) = 1 steps over 1 comma and is met by the prime digit 2;
a(2) = 2 steps over 2 commas and is met by the prime digit 5;
a(3) = 3 steps over 3 commas and is met by the prime digit 7;
a(4) = 5 steps over 5 commas and is met by the prime digit 2 (of "20");
a(5) = 4 steps over 4 commas and is met by the same prime digit 2 (of "20"); etc.

Crossrefs

Cf. A333406 (same idea, but the leftmost digit of the target is nonprime) and A333324 (leftmost digit is odd).

Sequence in context: A375375 A230086 A375374 * A227082 A227142 A246696

Adjacent sequences: A333401 A333402 A333403 * A333405 A333406 A333407

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, Mar 19 2020

Status

approved