A269851 a(0) = 1, a(A087686(1+n)) = 2*a(n), a(A088359(n)) = A250469(a(n)), where A088359 and A087686 = numbers that occur only once (resp. more than once) in A004001.

1, 2, 4, 3, 8, 9, 5, 6, 16, 21, 25, 7, 18, 15, 10, 12, 32, 45, 55, 49, 11, 42, 51, 35, 50, 27, 14, 36, 33, 30, 20, 24, 64, 93, 115, 91, 121, 13, 90, 123, 125, 77, 110, 147, 65, 98, 39, 22, 84, 105, 85, 102, 87, 70, 100, 57, 54, 28, 72, 69, 66, 60, 40, 48, 128, 189, 235, 203, 187, 169, 17, 186, 267, 305, 217, 143, 230

Offset: 0

Author

Antti Karttunen, Mar 07 2016

Keywords

• nonn

Comments

Permutation of natural numbers obtained from the sieve of Eratosthenes, combined with the permutation obtained from Hofstadter-Conway $10000 sequence (A004001). Note the indexing: Domain starts from 0, range from 1.

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8191
• Index entries for Hofstadter-type sequences
• Index entries for sequences that are permutations of the natural numbers
• Index entries for sequences generated by sieves

Crossrefs

Inverse: A269852.

Cf. A004001, A087686, A088359, A093879, A250469.

Related or similar permutations: A252755, A267111, A269855.

Formula

a(0) = 1, a(1) = 2, for n > 1, if A093879(n-1) = 0 [when n is in A087686], a(n) = 2*a(n - A004001(n)), otherwise [when n is in A088359], a(n) = A250469(a(A004001(n)-1)).

As a composition of related permutations:

a(n) = A252755(A267111(n)).

Other identities. For all n >= 0:

a(2^n) = 2^(n+1).