|
%I #16 Sep 08 2022 08:45:54
%S 2,6,42,546,9282,176358,4056234,117630786,4822862226,226674524622,
%T 13373796952698,1110025147073934,98792238089580126,
%U 9978016047047592726,1067647717034092421682,146267737233670661770434
%N Partial products of A181103.
%C a(n+1)-a(n) is divisible by 6 for n > 1.
%e First three terms of A181103 are 2, 3, 7, so a(3) = 2*3*7 = 42.
%o (Magma) A181103:=function(n); S:=[2, 3]; if n le 2 then return S[n]; end if; p:=5; for k in [3..n] do while not IsPrime(Abs(S[k-2]+S[k-1]-p)) do p:=NextPrime(p); end while; Append(~S, p); if k eq n then return p; end if; p:=NextPrime(p); end for; end function; A181737:=function(n); S:=[ A181103(k): k in [1..n] ]; T:=[ m eq 1 select S[1] else Self(m-1)*S[m]: m in [1..n] ]; return T[n]; end function; [ A181737(n): n in [1..20] ]; // _Klaus Brockhaus_, Dec 19 2010
%Y Cf. A181103.
%K nonn,easy
%O 1,1
%A _Giovanni Teofilatto_
|
