%I #6 Dec 14 2023 14:42:05
%S 0,1,2,7,8,5,14,31,32,17,10,23,56,29,62,127,128,65,34,71,40,21,46,95,
%T 224,113,58,119,248,125,254,511,512,257,130,263,136,69,142,287,160,81,
%U 42,87,184,93,190,383,896,449,226,455,232,117,238,479,992,497,250,503
%N Replace in the binary expansion of n each run of k 0's (or 1's) with 2k-1 0's (or 1's).
%e a(1) = 1, as 1 is 1 in binary and single runs stay intact (as 2*1 - 1 = 1). a(9) = 17, as 9 is 1001 in binary and keeping the most and the least significant runs as '1' and changing the center run '00' to '000', we get 10001 in binary, 17 in decimal.
%o (MIT/GNU Scheme)
%o ;;; binexp->runcount1list and runcount1list->binexp given in A129594.
%o (define (A129603 n) (runcount1list->binexp (map (lambda (i) (- (* 2 i) 1)) (binexp->runcount1list n))))
%Y Cf. A001196, A129602.
%K nonn,base
%O 0,3
%A _Antti Karttunen_, May 01 2007