A022020 - OEIS

%I #18 Feb 16 2016 11:08:10

%S 3,9,28,88,277,872,2746,8648,27236,85778,270153,850832,2679649,

%T 8439409,26579461,83710572,263641910,830325909,2615066456,8236010096,

%U 25938867499,81693057596,257287858063,810314166891,2552040558803,8037513448351,25313713063685,79724167578475

%N Define the sequence S(a(0),a(1)) by a(n+2) is the least integer such that a(n+2)/a(n+1) > a(n+1)/a(n) for n >= 0. This is S(3,9).

%H Colin Barker, <a href="/A022020/b022020.txt">Table of n, a(n) for n = 0..1000</a>

%p A022020 := proc(n)

%p     option remember;

%p     if n <= 1 then

%p         op(n+1,[3,9]) ;

%p     else

%p         a := procname(n-1)^2/procname(n-2) ;

%p         if type(a,'integer') then

%p             a+1 ;

%p         else

%p             ceil(a) ;

%p         fi;

%p     end if;

%p end proc: # _R. J. Mathar_, Feb 10 2016

%o (PARI) a=[3,9]; for(n=2,30,a=concat(a,a[n]^2\a[n-1]+1)); a \\ _M. F. Hasler_, Feb 10 2016

%K nonn

%O 0,1

%A _R. K. Guy_

%E Double-checked and extended to 3 lines of data by _M. F. Hasler_, Feb 10 2016