login
Inverse function of N -> N injection A083934.
7

%I #6 Jan 30 2024 04:37:38

%S 0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,3,0,0,0,0,0,0,0,0,0,0,0,

%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

%U 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0

%N Inverse function of N -> N injection A083934.

%C a(0)=0 because A083934(0)=0, but a(n) = 0 also for those n which do not occur as values of A083934. All positive natural numbers occur here once.

%o (MIT Scheme:) (define (A083935 n) (let* ((b (A014486 n)) (c (if (zero? (modulo b 3)) (A059905 (/ b 3)) 0))) (if (zero? (A059906 (/ b 3))) (A080300 c) 0)))

%Y a(A080934(n)) = n for all n. Cf. A083925-A083929, A014486, A080300, A059905, A059906.

%K nonn

%O 0,16

%A _Antti Karttunen_, May 13 2003