%I A103508
%S A103508 9,15,31,101,139,227,91,503,995,451,751,539,1819,1397,2957,3461,1831,
%T A103508 1417,6023,3769,1777,9587,5411,9421,18653,8089,4511,6541,10529,16051,
%U A103508 19049,13163,3139,22937,23929,43363,24919,43571,97367,55571,14419,75209
%N A103508 a(n) = 1 + 2 * least i such that A103507(i)=n+1, 0 if no such i exists.
%o A103508 (Scheme:) (define (A103508 n) (+ 1 (* 2 (first-n-where-fun_n-is-i1 A103507 
               (+ 1 n)))))
%o A103508 (define (first-n-where-fun_n-is-i1 fun i) (let loop ((n 1)) (cond ((= 
               i (fun n)) n) (else (loop (+ n 1))))))
%Y A103508 Cf. A103510, A103151, A103152, A103153, A103506, A103507, A025017.
%Y A103508 Sequence in context: A060874 A147511 A124580 this_sequence A051246 A062016 
               A108637
%Y A103508 Adjacent sequences: A103505 A103506 A103507 this_sequence A103509 A103510 
               A103511
%K A103508 nonn,hard
%O A103508 1,1
%A A103508 Lei Zhou (lzhou5(AT)emory.edu), Feb 10 2005
%E A103508 Edited and Scheme-code added by Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com), 
               Jun 19 2007