cp's OEIS Frontend

A046811 Numbers (with nonzero digits only) where A046810 increases.

%I A046811 #16 Apr 03 2025 02:52:18
%S A046811 1,2,13,113,149,1123,1237,11234,11239,12347,12359,12367,12379,13459,
%T A046811 13789,111389,112279,112337,112346,112348,112349,112379,112679,113789,
%U A046811 123457,123467,123469,123479,1112347,1112357,1112359,1113479,1122349
%N A046811 Numbers (with nonzero digits only) where A046810 increases.
%H A046811 Robert Israel, <a href="/A046811/b046811.txt">Table of n, a(n) for n = 1..86</a>
%e A046811 A046810(*) reaches 3 for the first time at 113.
%p A046811 S[1]:= [seq([i],i=1..9)]:
%p A046811 for d from 2 to 7 do S[d]:= map(t -> seq([i,op(t)],i=t[1]..9),S[d-1]) od:
%p A046811 f:= proc(L) local t,i;
%p A046811   add(`if`(isprime(add(t[i]*10^(i-1),i=1..nops(t))),1,0),t=combinat:-permute(L))
%p A046811 end proc:
%p A046811 R:= NULL: m:= -1:
%p A046811 for d from 1 to 7 do
%p A046811 for L in S[d] do
%p A046811     v:= f(L);
%p A046811     if v > m then m:= v;  x:= add(L[i]*10^(i-1),i=1..nops(L)); R:= R,x; fi
%p A046811 od od:
%p A046811 R; # _Robert Israel_, Mar 31 2025
%Y A046811 Cf. A009994, A046810, A052382.
%K A046811 nonn,base
%O A046811 1,2
%A A046811 _David W. Wilson_
%E A046811 Offset corrected by _Robert Israel_, Mar 31 2025