A246364 Permutation of natural numbers: a(n) = A064216(A227413(n)).

1, 2, 5, 3, 7, 11, 13, 4, 6, 9, 19, 14, 8, 12, 29, 10, 17, 31, 23, 16, 41, 71, 37, 44, 47, 39, 43, 42, 38, 30, 26, 59, 22, 34, 15, 85, 53, 58, 25, 130, 57, 151, 61, 311, 103, 69, 33, 365, 157, 111, 73, 226, 74, 106, 67, 370, 223, 56, 97, 341, 139, 122, 35, 133, 55, 86, 20, 145, 46, 49, 21, 659, 118, 36, 83, 419, 127, 191, 18

Offset: 1

Author

Antti Karttunen, Aug 26 2014

Keywords

• nonn

Comments

After a(2) = 2, the rest of the even bisection contains only terms of A246261. However, some of the terms of A246261 are also found in the odd bisection, while terms of A246263, apart from 2, all reside in the odd bisection of this sequence.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..4095
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Inverse: A246363.

Related or similar permutations: A064216, A227413, A246366, A246368.

Cf. A246261, A246263.

Programs

PARI

default(primelimit,(2^31)+(2^30));
A002808(n) = { my(k=-1); while( -n + n += -k + k=primepi(n), ); n }; \\ This function from M. F. Hasler
A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
A064216(n) = A064989((2*n)-1);
A227413(n) = if(1==n, 1, if(!(n%2), prime(A227413(n/2)), A002808(A227413((n-1)/2))));
A246364(n) = A064216(A227413(n));
for(n=1, 4095, write("b246364.txt", n, " ", A246364(n)));

Scheme

(define (A246364 n) (A064216 (A227413 n)))

Formula

a(n) = A064216(A227413(n)).