|
%I #8 Oct 04 2014 10:05:45
%S 0,1,2,3,4,6,7,11,13,14,21,25,27,28,41,48,52,54,55,79,93,100,104,106,
%T 107,152,179,193,200,204,206,207,293,345,372,386,393,397,399,400,565,
%U 665,717,744,758,765,769,771,772,1089,1282,1382,1434,1461,1475,1482
%N Differences of nonzero tetranacci numbers.
%C A113244 is the primes in the above sequence; namely prime differences of tetranacci numbers. Perfect powers in this sequence include: 4 = 2^2, 25 = 5^2, 27 = 3^3, 100 = 10^2 = 2^2 * 5^2, 400 = 20^2 = 2^4 * 5^2, 1089 = 33^2 = 3^2 * 11^2.
%H R. J. Mathar, <a href="/A113243/b113243.txt">Table of n, a(n) for n = 1..197</a>
%F {a(n)} = { A000078(i) - A000078(j) such that i>=j}. {a(n)} = nonnegative elements of the difference set of tetranacci sequence A000078.
%p isA113243 := proc(n)
%p local i,j ;
%p for j from 3 do
%p for i from 3 to j do
%p if A000078(j) - A000078(i) = n then
%p return true;
%p elif A000078(j) - A000078(i) < n then
%p break ;
%p end if;
%p end do:
%p if A000078(j) - A000078(j-1) > n then
%p return false;
%p end if;
%p end do:
%p end proc:
%p for n from 0 to 10000 do
%p if isA113243(n) then
%p printf("%d,",n) ;
%p end if;
%p end do: # _R. J. Mathar_, Oct 04 2014
%Y Cf. A000078, A113188-A113194, A113238, A113239, A113244.
%K easy,nonn
%O 1,3
%A _Jonathan Vos Post_, Oct 19 2005; corrected Oct 20 2005
|
