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 A134028 Reversal of n in balanced ternary representation. 12
 0, 1, -2, 1, 4, -11, -2, 7, -8, 1, 10, -5, 4, 13, -38, -11, 16, -29, -2, 25, -20, 7, 34, -35, -8, 19, -26, 1, 28, -17, 10, 37, -32, -5, 22, -23, 4, 31, -14, 13, 40, -119, -38, 43, -92, -11, 70, -65, 16, 97, -110, -29, 52, -83, -2, 79, -56, 25, 106, -101, -20, 61, -74, 7, 88, -47, 34, 115, -116, -35, 46, -89, -8, 73, -62, 19, 100 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS As the graph demonstrates, the sequence makes large negative steps at terms (3^i+1)/2. These steps divide the graph into conspicuous blocks. - N. J. A. Sloane, Jul 03 2016 REFERENCES D. E. Knuth, The Art of Computer Programming, Addison-Wesley, Reading, MA, Vol 2, pp 173-175. LINKS R. Zumkeller, Table of n, a(n) for n = 0..10000 Eric Weisstein's World of Mathematics, Reversal Wikipedia, Balanced Ternary FORMULA a(A134027(n)) = A134027(n); A134021(ABS(a(n))) <= A134021(n). EXAMPLE 20 = 1*3^3 - 1*3^2 + 1*3^1 - 1*3^0 == '+-+-' => a(20) = -1*3^3 + 1*3^2 - 1*3^1 + 1*3^0 = -20; 21 = 1*3^3 - 1*3^2 + 1*3^1 + 0*3^0 == '+-+0' => a(21) = 0*3^3 + 1*3^2 - 1*3^1 + 1*3^0 = 7; 22 = 1*3^3 - 1*3^2 + 1*3^1 + 1*3^0 == '+-++' => a(22) = 1*3^3 + 1*3^2 - 1*3^1 + 1*3^0 = 34; 23 = 1*3^3 + 0*3^2 - 1*3^1 - 1*3^0 == '+0--' => a(23) = -1*3^3 - 1*3^2 + 0*3^1 + 1*3^0 = -35; 24 = 1*3^3 + 0*3^2 - 1*3^1 + 0*3^0 == '+0-0' => a(24) = 0*3^3 - 1*3^2 + 0*3^1 + 1*3^0 = -8; 25 = 1*3^3 + 0*3^2 - 1*3^1 + 1*3^0 == '+0-+' => a(25) = 1*3^3 - 1*3^2 + 0*3^1 + 1*3^0 = 19. PROG (Python) def a(n):     if n==0: return 0     s=[]     x=0     while n>0:         x=n%3         n=n/3         if x==2:             x=-1             n+=1         s+=[x, ]     l=s[::-1]     t=0     for i in xrange(len(l)): t+=l[i]*3**i     return t print [a(n) for n in xrange(101)] # Indranil Ghosh, Jun 10 2017 CROSSREFS Cf. A117966 (balanced ternary representation), A030102, A134021, A274107. A134027 gives the numbers whose balanced ternary representation is palindromic. Sequence in context: A121198 A234599 A016544 * A111479 A323937 A088137 Adjacent sequences:  A134025 A134026 A134027 * A134029 A134030 A134031 KEYWORD sign,look,base AUTHOR Reinhard Zumkeller, Oct 19 2007 STATUS approved

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Last modified April 23 18:15 EDT 2019. Contains 322387 sequences. (Running on oeis4.)