A362343 - OEIS

%I #21 Apr 23 2023 02:19:05

%S 1,2,4,8,64,128,16384,32768,1073741824,2147483648,4611686018427387904,

%T 9223372036854775808,85070591730234615865843651857942052864,

%U 170141183460469231731687303715884105728,28948022309329048855892746252171976963317496166410141009864396001978282409984

%N Sequence that alternately doubles and squares the previous number; a(0) = 1.

%F a(0) = 1; a(n) = a(n-1)*2 if n is odd, otherwise a(n) = a(n-1)^2.

%F a(n) = 2^A075427(n-1), for n>=1.

%o (Python)

%o def A362343(n): return 1<<((1<<(n>>1)+1)-1 if n&1 else (1<<(n>>1)+1)-2) # _Chai Wah Wu_, Apr 23 2023

%Y Cf. A075427.

%Y Subsequence of A000079.

%K nonn,easy

%O 0,2

%A _Christopher Roat_, Apr 17 2023