A245607 - OEIS

%I #13 Jul 31 2014 23:49:56

%S 1,2,3,5,4,9,13,6,17,37,8,25,7,10,69,33,26,11,41,16,277,45,18,65,21,

%T 14,1109,15,52,73,57,74,35,209,82,293,141,34,53,329,12,1173,31,36,213,

%U 149,104,43,49,20,145,173,138,81,581,114,553,71,90,133,101,282,19,325,24,457,165,50,77,97,62,105,555,42

%N Permutation of natural numbers, the even bisection of A245605 halved: a(n) = A245605(2*n)/2.

%H Antti Karttunen, <a href="/A245607/b245607.txt">Table of n, a(n) for n = 1..10001</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%F a(n) = A245605(2*n)/2.

%F As a composition of related permutations:

%F a(n) = A245605(A064216(n)).

%F a(n) = A245705(A245707(n)).

%o (PARI)

%o A064989(n) = my(f = factor(n)); for(i=1, #f~, if((2 == f[i,1]),f[i,1] = 1,f[i,1] = precprime(f[i,1]-1))); factorback(f);

%o A245605(n) = if(1==n, 1, if(0==(n%2), 2*A245605(A064989(n-1)), 1+(2*A245605(A064989(n)-1))));

%o A245607(n) = A245605(2*n)/2;

%o for(n=1, 10001, write("b245607.txt", n, " ", A245607(n)));

%o (Scheme) (define (A245607 n) (A245605 (A064216 n)))

%Y Inverse: A245608.

%Y Cf. A064216, A064989, A245705, A245707, A245605, A245609-A245610, A245611, A244153, A243065-A243066.

%K nonn

%O 1,2

%A _Antti Karttunen_, Jul 29 2014