A140832 a(0) = 1; if a(n) is even, a(n + 1) = 5a(n)/2; if a(n) is odd, a(n + 1) is 5a(n)/2 rounded to the nearest even integer.

1, 2, 5, 12, 30, 75, 188, 470, 1175, 2938, 7345, 18362, 45905, 114762, 286905, 717262, 1793155, 4482888, 11207220, 28018050, 70045125, 175112812, 437782030, 1094455075, 2736137688, 6840344220, 17100860550, 42752151375, 106880378438

Offset

0,2

Links

Table of n, a(n) for n=0..28.

Mathematica

a[0] = 1; a[n_] := a[n] = If[IntegerQ[ 5a[n - 1]/2 ], 5a[n - 1]/2, If[IntegerQ[ Floor[5a[n - 1]/2]/2 ], Floor[5a[n - 1]/2], Ceiling[5a[n - 1]/2]]]
NestList[If[EvenQ[#], (5#)/2, Round[(5#)/2]]&, 1, 30] (* Harvey P. Dale, Dec 23 2011 *)

Crossrefs

Sequence in context: A054341 A000106 A076883 * A326793 A026580 A092247

Adjacent sequences: A140829 A140830 A140831 * A140833 A140834 A140835

Keyword

easy,nonn

Author

Joel B. Lewis, Jul 18 2008

Status

approved