OFFSET
1,2
COMMENTS
Only the 3x+1 steps, not the halving steps, are counted.
REFERENCES
D. R. Hofstadter, Goedel, Escher, Bach: an Eternal Golden Braid, Random House, 1980, p. 400.
G. T. Leavens and M. Vermeulen, 3x+1 search problems, Computers and Mathematics with Applications, 24 (1992), 79-99.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..71
Brian Hayes, Computer Recreations: On the ups and downs of hailstone numbers, Scientific American, 250 (No. 1, 1984), pp. 10-16.
FORMULA
Positions of records in A006667. - Sean A. Irvine, Jul 22 2020
MATHEMATICA
f[ nn_ ] := Module[ {c, n}, c = 0; n = nn; While[ n != 1, If[ Mod[ n, 2 ] == 0, n /= 2, n = 3*n + 1; c++ ] ]; Return[ c ] ] maxx = -1; For[ n = 1, n <= 10^8, n++, Module[ {val}, val = f[ n ]; If[ val > maxx, maxx = val; Print[ n, " ", val ] ] ] ] (* Winston C. Yang (winston(AT)cs.wisc.edu), Aug 27 2000 *)
PROG
(Haskell)
a033958 n = a033958_list !! (n-1)
-- For definition of a033958_list: see A033959.
-- Reinhard Zumkeller, Jan 08 2014
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
EXTENSIONS
More terms from Jud McCranie, Jan 26 2000
Corrected with Mathematica code by Winston C. Yang (winston(AT)cs.wisc.edu), Aug 27 2000
a(40)-a(43) from Charles R Greathouse IV, Oct 07 2013
STATUS
approved