A135381 a(n) = high point in trajectory of n under repeated application of powertrain map (see A133500).

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, 32, 531441, 128, 256, 512, 30, 31, 32, 128, 81, 5832000, 729, 30840979456, 191102976, 102372436321763328, 40, 41, 42, 531441, 256, 1024, 531441, 531441, 5832000, 8470728, 50, 51, 32, 125, 625

Offset

0,3

Links

N. J. A. Sloane, Table of n, a(n) for n = 0..10000

Example

The trajectory of 39 is 39 -> 19683 -> 5038848 -> 214990848 -> 17179869184 -> 1735247072139264 -> 19999187712 -> 102372436321763328 -> 8813365017182208 -> 0, so a(39) = 102372436321763328.

Maple

maxtraj := proc(n) local h, p, M, t1, t2, i; M:=100; t1:=n; h:=n; for i from 1 to M do t2:=powertrain(t1); if t2 = t1 then RETURN(n, h); fi; if t2 > t1 then h:=t2; fi; t1:=t2; od; RETURN(n, -1); end;

Crossrefs

Cf. A133500, A133501. For records see A135382, A135383.

Sequence in context: A050608 A260424 A090273 * A135382 A351831 A328617

Adjacent sequences: A135378 A135379 A135380 * A135382 A135383 A135384

Keyword

nonn,base

Author

J. H. Conway and N. J. A. Sloane, Dec 10 2007

Status

approved