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 A163241 Simple self-inverse permutation: Write n in base 4, then replace each digit '2' with '3' and vice versa, then convert back to decimal. 10
 0, 1, 3, 2, 4, 5, 7, 6, 12, 13, 15, 14, 8, 9, 11, 10, 16, 17, 19, 18, 20, 21, 23, 22, 28, 29, 31, 30, 24, 25, 27, 26, 48, 49, 51, 50, 52, 53, 55, 54, 60, 61, 63, 62, 56, 57, 59, 58, 32, 33, 35, 34, 36, 37, 39, 38, 44, 45, 47, 46, 40, 41, 43, 42, 64, 65, 67, 66, 68, 69, 71, 70 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS A. Karttunen, Table of n, a(n) for n = 0..1023 FORMULA a(n) = A000695(A003987bi(A059905(n),A059906(n))) + 2*A000695(A059906(n)), where A003987bi is binary XOR. EXAMPLE 43 in quaternary base (A007090) is written as '223' (2*16 + 2*4 + 3), which is then mapped to '332' = 3*16 + 3*4 + 2 = 62, thus a(43) = 62, and likewise a(62) = 43. MATHEMATICA Table[FromDigits[IntegerDigits[n, 4]/.{2->a, 3->b}/.{a->3, b->2}, 4], {n, 0, 75}] (* Harvey P. Dale, Nov 29 2011 *) PROG (Scheme) (define (A163241 n) (+ (A000695 (A003987bi (A059905 n) (A059906 n))) (* 2 (A000695 (A059906 n))))) (Python) def a000695(n):     n=bin(n)[2:]     x=len(n)     return sum([int(n[i])*4**(x - 1 - i) for i in range(x)]) def a059905(n): return sum([(n>>2*i&1)<

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Last modified August 2 10:15 EDT 2021. Contains 346422 sequences. (Running on oeis4.)