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

1, 2, 13, 113, 149, 1123, 1237, 11234, 11239, 12347, 12359, 12367, 12379, 13459, 13789, 111389, 112279, 112337, 112346, 112348, 112349, 112379, 112679, 113789, 123457, 123467, 123469, 123479, 1112347, 1112357, 1112359, 1113479, 1122349

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Examples

			A046810(*) reaches 3 for the first time at 113.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..86

Crossrefs

Cf. A009994, A046810, A052382.

Programs

Maple

S[1]:= [seq([i],i=1..9)]:
for d from 2 to 7 do S[d]:= map(t -> seq([i,op(t)],i=t[1]..9),S[d-1]) od:
f:= proc(L) local t,i;
  add(`if`(isprime(add(t[i]*10^(i-1),i=1..nops(t))),1,0),t=combinat:-permute(L))
end proc:
R:= NULL: m:= -1:
for d from 1 to 7 do
for L in S[d] do
    v:= f(L);
    if v > m then m:= v;  x:= add(L[i]*10^(i-1),i=1..nops(L)); R:= R,x; fi
od od:
R; # Robert Israel, Mar 31 2025

Extensions

Offset corrected by Robert Israel, Mar 31 2025