%I A154470
%S A154470 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,
%T A154470 26,27,28,32,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,
%U A154470 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,74
%N A154470 Rewriting function for Wolfram's e[x_][y_] -> x[x[y]] symbolic system 
               transformation, implemented on nihilistic S-expressions (parenthesizations) 
               encoded by A014486.
%C A154470 Here we use the empty list () as a marker for symbol 'e'. Any sublist 
               like (... ()(x1 x2 ... xn)(y1 y2 ... yn) ...) is transformed into 
               the form (... x1 x2 ... xn (x1 x2 ... xn (y1 y2 ... yn)) ...). A54471 
               gives the iterations of this function, starting from initial value 
               31706.
%H A154470 A. Karttunen, <a href="b154470.txt">Table of n, a(n) for n = 0..2055</
               a>
%H A154470 S. Wolfram, <a href="http://www.wolframscience.com/nksonline/page-102">
               A New Kind of Science, Wolfram Media Inc., (2002), pp. 102</a>--104, 
               896-898.
%o A154470 (Scheme:) (define (*A154470 s) (cond ((null? s) s) ((and (null? (car 
               s)) (>= (length s) 3) (pair? (second s)) (pair? (third s))) (append 
               (second s) (cons (append (second s) (list (third s))) (*A154470 (cdddr 
               s))))) (else (cons (*A154470 (car s)) (*A154470 (cdr s))))))
%Y A154470 Differs from A001477 for the first time at n=29, where a(n)=32.
%Y A154470 Sequence in context: A087143 A080683 A124231 this_sequence A090106 A167662 
               A135383
%Y A154470 Adjacent sequences: A154467 A154468 A154469 this_sequence A154471 A154472 
               A154473
%K A154470 nonn
%O A154470 0,3
%A A154470 Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com), Jan 11 2009