This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A056539 Self-inverse permutation: reverse the bits in binary expansion of n and also complement them (0->1, 1->0) if the run count (A005811) is even. 28
 0, 1, 2, 3, 6, 5, 4, 7, 14, 9, 10, 13, 12, 11, 8, 15, 30, 17, 22, 25, 26, 21, 18, 29, 28, 19, 20, 27, 24, 23, 16, 31, 62, 33, 46, 49, 54, 41, 38, 57, 58, 37, 42, 53, 50, 45, 34, 61, 60, 35, 44, 51, 52, 43, 36, 59, 56, 39, 40, 55, 48, 47, 32, 63, 126, 65, 94, 97, 110, 81, 78 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Paul Tek, Table of n, a(n) for n = 0..8191 FORMULA a(2n) = A036044(2n), a(2n+1) = A030101(2n+1). - Antti Karttunen, Feb 14 2003 EXAMPLE n: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 binary expansion: 0, 1, 10, 11, 100, 101, 110, 111,1000,1001,1010,1011,1100,1101,1110,1111 reversed/complemented: 0, 1, 10, 11, 110, 101, 100, 111,1110,1001,1010,1101,1100,1011,1000,1111 MAPLE [seq(runcounts2binexp(reverse(binexp2runcounts(j))), j=0..511)]; runcounts2binexp := proc(c) local i, e, n; n := 0; for i from 1 to nops(c) do e := c[i]; n := ((2^e)*n) + ((i mod 2)*((2^e)-1)); od; RETURN(n); end; binexp2runcounts := proc(nn) local n, a, p, c; n := nn; a := []; p := (`mod`(n, 2)); c := 0; while(n > 0) do c := c+1; n := floor(n/2); if((`mod`(n, 2)) <> p) then a := [c, op(a)]; c := 0; p := (`mod`(p+1, 2)); fi; od; RETURN(a); end; # reverse given in A056538 PROG (Python) def a005811(n): return bin(n^(n>>1))[2:].count("1") def a(n):     if n==0: return 0     x=bin(n)[2:][::-1]     if a005811(n)%2==1: return int(x, 2)     z=''.join('1' if i == '0' else '0' for i in x)     return int(z, 2) # Indranil Ghosh, Apr 29 2017 CROSSREFS Cf. A054429. When restricted to A014486 induces another permutation, A057164. A105726 is a "deep" variant. Sequence in context: A305418 A284459 A106451 * A105726 A284460 A175949 Adjacent sequences:  A056536 A056537 A056538 * A056540 A056541 A056542 KEYWORD base,nonn,look AUTHOR Antti Karttunen, Jun 20, 2000 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 18 06:04 EST 2019. Contains 320245 sequences. (Running on oeis4.)