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Binary concatenation (ignoring leading zeros) of a(n-1) and a(n-2) mod n, starting with a(n) = n for n <= 1.
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%I #17 Mar 27 2020 16:38:05

%S 0,1,1,0,1,1,3,0,3,3,5,1,1,3,7,1,15,14,5,18,9,12,3,14,11,15,17,17,1,

%T 20,11,0,11,11,17,3,5,23,37,37,5,29,27,33,27,6,35,4,3,28,15,49,19,46,

%U 33,13,25,14,9,40,49,4,57,19,57,23,11,40,39,52,7,3,31

%N Binary concatenation (ignoring leading zeros) of a(n-1) and a(n-2) mod n, starting with a(n) = n for n <= 1.

%C Value 0 is treated as empty bit string.

%H Alois P. Heinz, <a href="/A333453/b333453.txt">Table of n, a(n) for n = 0..32768</a>

%F a(n) = (a(n-1)*A062383(a(n-2)) + a(n-2)) mod n if n > 1, a(n) = n if n < 2.

%e a(18) = 5 = 239 mod 18, where 239 = 11101111_2 is the binary concatenation 1110_2 = 14 = a(17) and 1111_2 = 15 = a(16).

%p a:= proc(n) option remember; `if`(n<2, n, (t-> a(n-1)*

%p `if`(t=0, 1, 2^(ilog2(t)+1))+t)(a(n-2)) mod n)

%p end:

%p seq(a(n), n=0..100);

%Y Cf. A062383, A063896, A079777.

%K nonn,base

%O 0,7

%A _Alois P. Heinz_, Mar 21 2020