A263048 - OEIS

%I #33 May 02 2023 16:32:11

%S 0,1,1,2,3,17,129145076

%N a(0)=0, a(1)=1; for n>1, a(n) = a(n-2)^a(n-1) + a(n-1)^a(n-2).

%C Next term has 365895553 digits.

%t RecurrenceTable[{a[0] == 0, a[1] == 1, a[n] == a[n-2]^a[n-1]+a[n-1]^a[n-2]}, a, {n, 6}] (* _Vincenzo Librandi_, Oct 09 2015 *)

%t nxt[{a_,b_}]:={b,a^b+b^a}; NestList[nxt,{0,1},6][[;;,1]] (* _Harvey P. Dale_, May 02 2023 *)

%o (PARI) a(n) = if(n<2, n, a(n-2)^a(n-1)+a(n-1)^a(n-2)) \\ _Altug Alkan_, Oct 15 2015

%o (Magma) [n le 2 select n-1 else Self(n-2)^Self(n-1)+Self(n-1)^Self(n-2): n in [1..7]]; // _Vincenzo Librandi_, Oct 09 2015

%K nonn

%O 0,4

%A _Gianmarco Giordano_, Oct 08 2015