cp's OEIS Frontend

A372607 Let a(1) = 2, f(n) = a(1)*a(2)*...*a(n-1) for n >= 1 and a(n) = nextludicnumber(f(n)+1) - f(n) for n >= 2, where nextludicnumber(x) is the smallest ludic number > x.

%I A372607 #21 Nov 06 2024 04:44:09
%S A372607 2,3,5,7,11,23,13,25,17
%N A372607 Let a(1) = 2, f(n) = a(1)*a(2)*...*a(n-1) for n >= 1 and a(n) = nextludicnumber(f(n)+1) - f(n) for n >= 2, where nextludicnumber(x) is the smallest ludic number > x.
%C A372607 Conjecture: every element is a ludic number.
%C A372607 This is the analog of Buss' conjecture (cf. A067836) for ludic numbers instead of primes, and similar to the idea of ludic Fortunate numbers (A376237) in analogy to the usual Fortunate numbers A005235. - _M. F. Hasler_, Nov 04 2024
%o A372607 (PARI) A372607_upto(n=15, f=1)=vector(n,i,n=if(i>1, next_A003309(1+f*=n)-f,2)) \\ _M. F. Hasler_, Nov 02 2024
%Y A372607 Cf. A067836, A003309 (ludic numbers), A376237 (ludic Fortunate numbers).
%K A372607 nonn,more,hard
%O A372607 1,1
%A A372607 _Davide Rotondo_, May 07 2024