login
A259656
Let f(x) be the absolute value of the difference between x and its base-2 reversal. a(n) is the number of times f(x) must be applied starting with n for the result to be 0.
2
1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 3, 2, 3, 2, 1, 2, 1, 2, 3, 2, 1, 2, 3, 2, 3, 2, 1, 2, 3, 2, 1, 2, 1, 2, 3, 2, 3, 4, 3, 4, 3, 2, 3, 2, 1, 2, 3, 2, 3, 2, 1, 4, 3, 2, 3, 4, 3, 4, 3, 2, 3, 2, 1, 2, 1, 2, 3, 2, 3, 2, 3, 2, 1, 2, 3, 2, 3, 2, 3, 4, 3, 2, 3
OFFSET
1,2
COMMENTS
First differences appear to always be odd.
More precisely, a(n) is even if n is even and a(n) is odd when n is odd. This is an immediate consequence of the parities in A055945 (which represents f apart from the sign) and the fact that we count iterations of f until the result is even. - Jörgen Backelin, Nov 04 2015
MAPLE
A259656 := proc(n)
local f, a ;
f := n ;
a := 0 ;
while f <> 0 do
f := abs(A055945(f)) ;
a := a+1 ;
end do:
a;
end proc: # R. J. Mathar, Nov 04 2015
CROSSREFS
Cf. A055945.
Sequence in context: A235431 A354599 A303536 * A096370 A330721 A076622
KEYWORD
nonn,base
AUTHOR
Dylan Hamilton, Jul 02 2015
STATUS
approved