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!)
 A244152 Self-inverse permutation of natural numbers: a(1) = 1; thereafter, if n is k-th number with an odd number of prime divisors (counted with multiplicity) [i.e., n = A026424(k)], a(n) = A028260(1+a(k)), otherwise, when n is k-th number > 1 with an even number of prime divisors [i.e., n = A028260(1+k)], a(n) = A026424(a(k)). 6
 1, 4, 10, 2, 24, 7, 6, 55, 18, 3, 16, 15, 121, 44, 12, 11, 39, 9, 36, 35, 105, 31, 250, 5, 29, 28, 93, 26, 25, 86, 22, 82, 238, 79, 20, 19, 81, 72, 17, 68, 218, 65, 517, 14, 62, 67, 60, 202, 195, 57, 59, 56, 185, 477, 8, 52, 50, 175, 51, 47, 177, 45, 495, 167, 42, 161, 46, 40, 162, 169, 150, 38, 143, 455, 459, 140, 153, 1060, 34, 134, 37, 32 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10001 FORMULA a(1) = 1, and for n > 1, if A066829(n) = 1, then a(n) = A028260(1 + A244152(A055038(n))), otherwise a(n) = A026424(A244152(A055037(n)-1)). For all n > 1, A008836(a(n)) = -1 * A008836(n), where A008836 is Liouville's lambda-function. PROG (Scheme, with memoization macro definec) (definec (A244152 n) (cond ((= 1 n) 1) ((= 1 (A066829 n)) (A028260 (+ 1 (A244152 (A055038 n))))) (else (A026424 (A244152 (-1+ (A055037 n))))))) CROSSREFS Cf. A008836, A026424, A028260, A055037, A055038, A066829. Similar entanglement permutations: A245603-A245604, A235491, A236854, A243347, A244319. Sequence in context: A016488 A087212 A048870 * A070261 A054048 A121512 Adjacent sequences:  A244149 A244150 A244151 * A244153 A244154 A244155 KEYWORD nonn AUTHOR Antti Karttunen, Jul 27 2014 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 February 19 13:25 EST 2020. Contains 332044 sequences. (Running on oeis4.)