Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Feb 28 2021 09:54:49
%S 0,1,2,10,3,11,4,5,12,13,14,6,7,15,16,8,9,17,18,19,20,21,30,31,32,100,
%T 40,41,42,101,43,102,103,104,44,45,46,47,48,49,50,51,52,105,106,53,
%U 107,54,60,61,62,108,63,109,64,65,110,66,67,68,69,70,71,72,111,73,112,113,114,74,75,115,116
%N When a digit d is prime, the next digit is < d.
%C After a(1) = 0, the sequence is always extended with the smallest positive integer not yet present that doesn't lead to a contradiction.
%H Rémy Sigrist, <a href="/A342047/b342047.txt">Table of n, a(n) for n = 1..10000</a>
%H Rémy Sigrist, <a href="/A342047/a342047.gp.txt">PARI program for A342047</a>
%o (PARI) See Links section.
%Y Cf. A342042, A342043, A342044, A342045 and A342046 (variations on the same idea).
%K base,nonn
%O 1,3
%A _Eric Angelini_, Feb 26 2021