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 A133048 Powerback(n): reverse the decimal expansion of n, drop any leading zeros, then apply the powertrain map of A133500 to the resulting number. 9
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 1, 4, 9, 16, 25, 36, 49, 64, 81, 3, 1, 8, 27, 64, 125, 216, 343, 512, 729, 4, 1, 16, 81, 256, 625, 1296, 2401, 4096, 6561, 5, 1, 32, 243, 1024, 3125, 7776, 16807, 32768, 59049, 6, 1, 64, 729, 4096, 15625, 46656, 117649 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS a(A221221(n)) = A133500(A221221(n)) = A222493(n). - Reinhard Zumkeller, May 27 2013 LINKS N. J. A. Sloane, Table of n, a(n) for n = 0..10000 EXAMPLE E.g. 240 -> (0)42 -> 4^2 = 16; 12345 -> 54321 -> 5^4*3^2*1 = 5625. MAPLE powerback:=proc(n) local a, i, j, t1, t2, t3; if n = 0 then RETURN(0); fi; t1:=convert(n, base, 10); t2:=nops(t1); for i from 1 to t2 do if t1[i] > 0 then break; fi; od: a:=1; t3:=t2-i+1; for j from 0 to floor(t3/2)-1 do a := a*t1[i+2*j]^t1[i+2*j+1]; od: if t3 mod 2 = 1 then a:=a*t1[t2]; fi; RETURN(a); end; PROG (Haskell) a133048 0 = 0 a133048 n = train \$ dropWhile (== 0) \$ a031298_row n where    train []       = 1    train [x]      = x    train (u:v:ws) = u ^ v * (train ws) -- Reinhard Zumkeller, May 27 2013 CROSSREFS Cf. A131571 (fixed points), A133059 and A133134 (records); A133500 (powertrain). Cf. A133144 (length of trajectory), A031346 and A003001 (persistence). Cf. A031298. Sequence in context: A004427 A113230 A065881 * A214950 A054055 A067456 Adjacent sequences:  A133045 A133046 A133047 * A133049 A133050 A133051 KEYWORD nonn,base AUTHOR J. H. Conway and N. J. A. Sloane, Dec 31 2007 STATUS approved

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Last modified January 21 15:00 EST 2019. Contains 319350 sequences. (Running on oeis4.)