Search: id:A153142
Results 1-1 of 1 results found.

%I A153142
%S A153142 0,1,3,2,6,7,5,4,12,13,14,15,10,11,9,8,24,25,26,27,28,29,30,31,20,21,
%T A153142 22,23,18,19,17,16,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,40,
%U A153142 41,42,43,44,45,46,47,36,37,38,39,34,35,33,32,96,97,98,99,100,101,102
%N A153142 Permutation of nonnegative integers: A059893-conjugate of A153152.
%C A153142 This sequence can be also obtained by starting complementing n's binary 
               expansion from the second most significant bit, continuing towards 
               lsb-end until the first 0-bit is reached, which is the last bit to 
               be complemented.
%H A153142 A. Karttunen, <a href="b153142.txt">Table of n, a(n) for n = 0..2047</
               a>
%H A153142 <a href="Sindx_Per.html#IntegerPermutation">Index entries for sequences 
               that are permutations of the natural numbers</a>
%e A153142 29 = 11101 in binary. By complementing bits in (zero-based) positions 
               3, 2 and 1 we get 10011 in binary, which is 19 in decimal, thus a(29)=19.
%o A153142 (MIT Scheme:) (define (a153142 n) (if (< n 2) n (let loop ((maskbit (a072376 
               n)) (z n)) (cond ((zero? maskbit) z) ((zero? (modulo (floor->exact 
               (/ n maskbit)) 2)) (+ z maskbit)) (else (loop (floor->exact (/ maskbit 
               2)) (- z maskbit)))))))
%Y A153142 Inverse: A153141. a(n) = A059893(A153152(A059893(n))) = A059894(A153151(A059894(n))). 
               Differs from A003188 for the first time at n=10, where a(10)=14 while 
               A003188(10)=15. Cf. also A072376. Corresponds to A069768 in the group 
               of Catalan bijections.
%Y A153142 Sequence in context: A165199 A120231 A083362 this_sequence A154447 A003188 
               A154435
%Y A153142 Adjacent sequences: A153139 A153140 A153141 this_sequence A153143 A153144 
               A153145
%K A153142 nonn,base
%O A153142 0,3
%A A153142 Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com), Dec 20 2008

Search completed in 0.001 seconds