A113243 Differences of nonzero tetranacci numbers.

0, 1, 2, 3, 4, 6, 7, 11, 13, 14, 21, 25, 27, 28, 41, 48, 52, 54, 55, 79, 93, 100, 104, 106, 107, 152, 179, 193, 200, 204, 206, 207, 293, 345, 372, 386, 393, 397, 399, 400, 565, 665, 717, 744, 758, 765, 769, 771, 772, 1089, 1282, 1382, 1434, 1461, 1475, 1482

Offset

1,3

Comments

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.

Links

R. J. Mathar, Table of n, a(n) for n = 1..197

Formula

{a(n)} = { A000078(i) - A000078(j) such that i>=j}. {a(n)} = nonnegative elements of the difference set of tetranacci sequence A000078.

Maple

isA113243 := proc(n)
    local i, j ;
    for j from 3 do
        for i from 3 to j do
            if A000078(j) - A000078(i) = n then
                return true;
            elif A000078(j) - A000078(i) < n then
                break ;
            end if;
        end do:
        if A000078(j) - A000078(j-1) > n then
            return false;
        end if;
    end do:
end proc:
for n from 0 to 10000 do
    if isA113243(n) then
        printf("%d, ", n) ;
    end if;
end do: # R. J. Mathar, Oct 04 2014

Crossrefs

Cf. A000078, A113188-A113194, A113238, A113239, A113244.

Sequence in context: A339510 A191930 A202113 * A130690 A308189 A074885

Adjacent sequences: A113240 A113241 A113242 * A113244 A113245 A113246

Keyword

easy,nonn

Author

Jonathan Vos Post, Oct 19 2005; corrected Oct 20 2005

Status

approved