A342958 a(n) is the least prime that starts a string of exactly n primes p_1, p_2, ... p_n where p_{i+1} = p_i-A003132(p_i), but p_n-A003132(p_n) is not prime.
2, 13, 547, 10559, 246349, 20020109, 20020163
Offset: 1
Examples
a(3) = 547 because 547, 547-A003132(547) = 457, and 457-A003132(457) = 367 are prime, but 367-A003132(367) = 273 is not prime.
Programs
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Maple
f:= proc(n) option remember; local t, x; x:= n - add(t^2, t=convert(n, base, 10)); if not isprime(x) then 1 else 1+procname(x) fi end proc: V:= Vector(7): count:= 0: p:= 1: while count < 7 do p:= nextprime(p); v:= f(p); if v <= N and V[v] = 0 then V[v]:= p; count:= count+1 fi od: convert(V, list);
Comments