A340744 - OEIS

%I #8 Jan 19 2021 04:48:28

%S 31,23,19,43,73,53,43,37,61,43,83,73,43,73,53,67,79,73,61,59,173,151,

%T 109,223,163,109,127,109,109,233,109,109,163,139,113,109,109,181,109,

%U 109,523,353,199,383,331,199,223,313,199,173,163,271,229,211,199,199,751,503,433,307,229,313,2411

%N Primes in A340618, in the order in which they occur.

%F a(n) = A316650(A340618(n)).

%e a(4) = A316650(23) = 43 is the fourth term in A316650 that is prime.

%p f:= proc(n) local a, b, c,p;

%p   c:= convert(convert(n, base, 10), `+`);

%p   a:= floor(n/c);

%p   b:= n mod c;

%p   p:= 10^(1+ilog10(b))*a+b;

%p   if isprime(p) then p fi;

%p end proc:

%p map(f, [$1..1000]);

%Y Cf. A316650, A340618.

%K nonn,look

%O 1,1

%A _J. M. Bergot_ and _Robert Israel_, Jan 18 2021