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A113243 Differences of nonzero tetranacci numbers. 2
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 (list; graph; refs; listen; history; text; internal format)
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: A226538 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

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Last modified May 27 21:52 EDT 2020. Contains 334671 sequences. (Running on oeis4.)