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A246364 Permutation of natural numbers: a(n) = A064216(A227413(n)). 6
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
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
FORMULA
a(n) = A064216(A227413(n)).
PROG
(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))));
for(n=1, 4095, write("b246364.txt", n, " ", A246364(n)));
(Scheme) (define (A246364 n) (A064216 (A227413 n)))
CROSSREFS
Inverse: A246363.
Related or similar permutations: A064216, A227413, A246366, A246368.
Sequence in context: A288417 A159016 A289108 * A352774 A083190 A171026
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 26 2014
STATUS
approved

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Last modified April 19 03:30 EDT 2024. Contains 371782 sequences. (Running on oeis4.)