A151898 First differences of Frobenius numbers for 7 successive numbers A138987.

1, 1, 1, 1, 1, 9, 2, 2, 2, 2, 2, 16, 3, 3, 3, 3, 3, 23, 4, 4, 4, 4, 4, 30, 5, 5, 5, 5, 5, 37, 6, 6, 6, 6, 6, 44, 7, 7, 7, 7, 7, 51, 8, 8, 8, 8, 8, 58, 9, 9, 9, 9, 9, 65, 10, 10, 10, 10, 10, 72, 11, 11, 11, 11, 11, 79, 12, 12, 12, 12, 12, 86, 13, 13, 13, 13, 13, 93, 14, 14, 14, 14, 14, 100, 15

Offset

1,6

Links

Table of n, a(n) for n=1..85.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,2,0,0,0,0,0,-1).

Formula

a(n) = A138987(n+1)-A138987(n).

G.f.: -x*(2*x^11-9*x^5-x^4-x^3-x^2-x-1) / ((x-1)^2*(x+1)^2*(x^2-x+1)^2*(x^2+x+1)^2). - Colin Barker, Dec 13 2012

Mathematica

a = {}; Do[AppendTo[a, FrobeniusNumber[{n + 1, n + 2, n + 3, n + 4, n + 5, n + 6, n + 7}]], {n, 1, 100}]; Differences[a]
Differences[Table[FrobeniusNumber[Range[n, n+6]], {n, 2, 90}]] (* or *) LinearRecurrence[ {0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, -1}, {1, 1, 1, 1, 1, 9, 2, 2, 2, 2, 2, 16}, 90] (* Harvey P. Dale, Jul 26 2024 *)

Crossrefs

For first differences of Frobenius numbers for k successive numbers see: A005843 (k=2), A014682 (k=3), A138995 (k=4), A138996 (k=5), A138997 (k=6), A151898 (k=7), A138999 (k=8).

Cf. A028387, A037165, A079326, A138985, A138986, A138987, A138988.

Cf. A138989, A138990, A138991, A138992, A138993, A138994.

Sequence in context: A335086 A388454 A388838 * A379385 A080994 A392290

Adjacent sequences: A151895 A151896 A151897 * A151899 A151900 A151901

Keyword

nonn,easy

Author

Artur Jasinski, Apr 05 2008

Status

approved