|
%I #6 Mar 03 2016 22:50:47
%S 1,1,2,1,3,2,5,1,4,3,7,2,11,5,6,1,13,4,9,3,8,7,17,2,23,11,10,5,25,6,
%T 19,1,12,13,15,4,29,9,14,3,37,8,41,7,16,17,43,2,21,23,18,11,47,10,31,
%U 5,20,25,35,6,53,19,22,1,27,12,61,13,24,15,67,4,55,29,26,9,71,14,33,3,28,37,77,8,49,41,30,7,83,16,89,17,32,43,39,2
%N a(1) = 1, after which, for odd numbers: a(n) = A260739(n)-th number k for which A260738(k) = A260738(n)-1, and for even numbers: a(n) = a(n/2).
%C For odd numbers n > 1, a(n) tells which term is on the immediately preceding row of A255127 (square array generated by Ludic sieve), in the same column where n itself is.
%H Antti Karttunen, <a href="/A269380/b269380.txt">Table of n, a(n) for n = 1..33011</a>
%F a(1) = 1; after which, for even numbers a(n) = a(n/2), and for odd numbers a(n) = A255127(A260738(n)-1, A260739(n)).
%F Other identities. For all n >= 1:
%F a(A269379(n)) = n.
%o (definec (A269380 n) (cond ((= 1 n) n) ((even? n) (A269380 (/ n 2))) (else (A255127bi (- (A260738 n) 1) (A260739 n))))) ;; Code for A255127bi given in A255127.
%Y Cf. A255127, A260738, A260739.
%Y Cf. A269172, A269355, A269357, A269382, A269386, A269388 (sequences that use this function).
%Y Cf. also A268674, A269370.
%K nonn
%O 1,3
%A _Antti Karttunen_, Mar 01 2016
|
