The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A269847 Permutation of natural numbers: a(1) = 1, for n > 1, if n is an odd prime, a(n) = A003961(a(A000720(n)), otherwise a(n) = 2*a(n-A000720(n)). 4
 1, 2, 3, 4, 5, 6, 9, 8, 10, 12, 7, 18, 15, 16, 20, 24, 25, 14, 27, 36, 30, 32, 21, 40, 48, 50, 28, 54, 45, 72, 11, 60, 64, 42, 80, 96, 75, 100, 56, 108, 35, 90, 81, 144, 22, 120, 63, 128, 84, 160, 192, 150, 135, 200, 112, 216, 70, 180, 49, 162, 33, 288, 44, 240, 126, 256, 125, 168, 320, 384, 225, 300, 105, 270, 400 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10000 FORMULA a(1) = 1, and for n > 1, if n is an odd prime, a(n) = A003961(a(A000720(n)), otherwise [when n is 2 or composite] a(n) = 2*a(n-A000720(n)). a(1) = 1; if n is an odd prime, a(n) = A003961(a(A026233(n)), else a(n) = A005843(a(A026233(n))). Declarative definition: a(1)=1, a(A065091(n)) = A003961(a(n+1)), a(A065090(n+1)) = 2*a(n). As a composition of other permutations: a(n) = A163511(A071574(n)). Other identities. For all n >= 1: a(A007097(n)) = A000040(n). [Maps the terms of primeth recurrence to primes.] PROG (Scheme, with memoization-macro definec) (definec (A269847 n) (cond ((<= n 1) n) ((and (odd? n) (= 1 (A010051 n))) (A003961 (A269847 (A000720 n)))) (else (* 2 (A269847 (- n (A000720 n))))))) CROSSREFS Inverse: A269848. Cf. A000040, A000720, A003961, A005843, A007097, A010051, A026233, A065090, A065091. Related or similar permutations: A071574, A163511, A246681, A257730, A269857. Sequence in context: A332815 A005941 A269857 * A245705 A075164 A240827 Adjacent sequences:  A269844 A269845 A269846 * A269848 A269849 A269850 KEYWORD nonn AUTHOR Antti Karttunen, Mar 06 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 26 08:16 EDT 2021. Contains 347664 sequences. (Running on oeis4.)