%I #15 Dec 09 2024 11:03:00
%S 23,29,37,43,53,59,73,79,83,97,233,239,263,283,293,379,397,439,443,
%T 463,523,563,593,599,643,653,739,743,773,823,839,853,883,929,937,953,
%U 983,997,2333,2339,2383,2393,2399,2633,2663,2683,2693,2833,2939,2963,4463
%N Primes which remain prime after operation "omit leftmost maximal digit" repeated until only one digit remains.
%C The least digit of a term must be a prime, and can occur only once in the term. - _Robert Israel_, Dec 08 2024
%H Robert Israel, <a href="/A101802/b101802.txt">Table of n, a(n) for n = 1..1250</a> (full sequence)
%e 9929 is a member because 9929, 929, 29 and 2 are all prime.
%p insert:= proc(L,d,pos)
%p local Lp, i;
%p Lp:= [op(L[1..pos]),d,op(L[pos+1..-1])];
%p add(Lp[i]*10^(i-1),i=1..nops(Lp))
%p end proc:
%p extend:= proc(n) local L,dmax,jmax,d,i,S;
%p L:= convert(n,base,10);
%p dmax:= max(L);
%p for jmax from nops(L) by -1 do if L[jmax] = dmax then break fi od;
%p S:= [seq(seq(insert(L,d,i),d=dmax+1..9),i=0..nops(L)),
%p seq(insert(L,dmax,i),i=jmax..nops(L))];
%p op(sort(select(isprime,S)))
%p end proc:
%p A[1]:= [2,3,5,7]:
%p dmax:= 5: # for terms of up to dmax digits
%p for i from 2 to dmax do
%p A[i]:= sort(map(extend,A[i-1]));
%p od:
%p map(op,[seq(A[i],i=2..dmax)]); # _Robert Israel_, Dec 09 2024
%K base,nonn,fini,full
%O 1,1
%A _Zak Seidov_, Jan 27 2005
%E Name clarified by _Robert Israel_, Dec 08 2024