A284213 The successive digits of the sequence are the same digits that have a nonprime rank in the sequence.

0, 1, 2, 10, 20, 102, 30, 3, 1020, 300, 31, 40, 2030, 50, 4, 3140, 200, 301, 5, 60, 43, 6, 140, 2000, 3015, 7, 600, 436, 11, 402, 70, 100, 3010, 57, 6000, 4360, 1140, 270, 8, 1000, 310, 101, 51, 760, 400, 43601, 1402, 700, 810, 500, 3100, 110, 15, 17, 6040, 80, 9, 436010, 14027, 800, 81, 10500, 13, 1001, 21, 90, 151, 76040, 18

Offset

1,3

Comments

The sequence is started with a(1) = 0 and always extended with the smallest integer not yet present and not leading to a contradiction.

Links

Table of n, a(n) for n=1..69.

Example

The first 12 terms are:
0,1,2,10,20,102,30,3,1020,300,31,40
Their successive digits are:
0,1,2,1,0,2,0,1,0,2,3,0,3,1,0,2,0,3,0,0,3,1,4,0
The nonprime rank digits are here (between parentheses):
(0),1,2,(1),0,(2),0,(1),(0),(2),3,(0),3,(1),(0),(2),0,(3),0,(0),(3),(1),4,(0),
Erasing the digits not in the parentheses:
(0),.,.,(1),.,(2),.,(1),(0),(2),.,(0),.,(1),(0),(2),.,(3),.,(0),(3),(1),.,(0),
The surviving digits are:
0,1,2,1,0,2,0,1,0,2,3,0,3,1,0,...
Those are indeed the digits of the starting sequence.

Crossrefs

Sequence in context: A294493 A261660 A004643 * A156818 A037422 A136735

Adjacent sequences: A284210 A284211 A284212 * A284214 A284215 A284216

Keyword

nonn,base

Author

Eric Angelini and Jean-Marc Falcoz, Mar 23 2017

Status

approved