cp's OEIS Frontend

A356084 Matula-Goebel number of the complete quaternary (4-ary) tree of n levels.

%I A356084 #6 Jul 27 2022 10:36:22
%S A356084 1,16,7890481,379723559137648771815613388050801
%N A356084 Matula-Goebel number of the complete quaternary (4-ary) tree of n levels.
%F A356084 a(n) = prime(a(n-1))^4, for n>=2.
%e A356084 For n=3, the complete quaternary tree of 3 levels is
%e A356084               7890481
%e A356084         /     /      \     \      a(4) = prime(16)^4
%e A356084      16      16      16      16        = 7890481
%e A356084    // \\   // \\   // \\   // \\
%e A356084   1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
%o A356084 (PARI) a(n) = my(ret=1); for(i=2,n, ret=prime(ret)^4); ret;
%Y A356084 Cf. A007097, A356082 (binary), A356083 (ternary).
%K A356084 nonn,more
%O A356084 1,2
%A A356084 _Kevin Ryde_, Jul 27 2022