

A306375


Lexicographically earliest sequence starting with a(1) = 12 with no duplicate terms such that [a(n)  (the nth digit of the sequence)] is prime.


1



12, 4, 6, 8, 10, 3, 2, 5, 7, 16, 9, 14, 11, 20, 18, 15, 24, 30, 13, 17, 32, 19, 38, 22, 21, 23, 26, 29, 42, 34, 44, 36, 40, 25, 48, 28, 46, 27, 31, 33, 39, 54, 43, 50, 45, 35, 49, 52, 41, 55, 56, 47, 51, 57, 62, 37, 63, 53, 61, 58, 65, 67, 69, 75, 71, 59, 73, 60, 64, 68, 70, 74, 76, 80, 66, 77, 83, 82, 72, 79, 87, 78, 86, 84
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OFFSET

1,1


COMMENTS

Any a(1) < 12 would be in contradiction with the definition.


LINKS



EXAMPLE

The sequence starts with 12,4,6,8,10,3,2,5,7,16,9,14,11,20,18,15,...
a(1) = 12 and [12  1 (the 1st digit of the sequence)] = 11 (prime);
a(2) = 4 and [ 4  2 (the 2nd digit of the sequence)] = 2 (prime);
a(3) = 6 and [ 6  4 (the 3rd digit of the sequence)] = 2;
a(4) = 8 and [ 8  6 (the 4th digit of the sequence)] = 2;
a(5) = 10 and [10  8 (the 5th digit of the sequence)] = 2;
a(6) = 3 and [ 3  1 (the 6th digit of the sequence)] = 2;
a(7) = 2 and [ 2  0 (the 7th digit of the sequence)] = 2;
a(8) = 5 and [ 5  3 (the 8th digit of the sequence)] = 2;
a(9) = 7 and [ 7  2 (the 9th digit of the sequence)] = 5 (prime);
etc.


CROSSREFS

Cf. A306321 where the same idea is used.


KEYWORD

base,nonn


AUTHOR



STATUS

approved



