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A138987 a(n) = Frobenius number for 7 successive numbers = F(n+1,n+2,n+3,n+4,n+5,n+6,n+7). 17
1, 2, 3, 4, 5, 6, 15, 17, 19, 21, 23, 25, 41, 44, 47, 50, 53, 56, 79, 83, 87, 91, 95, 99, 129, 134, 139, 144, 149, 154, 191, 197, 203, 209, 215, 221, 265, 272, 279, 286, 293, 300, 351, 359, 367, 375, 383, 391, 449, 458, 467, 476, 485, 494, 559, 569, 579, 589, 599 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For Frobenius numbers for 2 successive numbers see A028387

For Frobenius numbers for 3 successive numbers see A079326

For Frobenius numbers for 4 successive numbers see A138984

For Frobenius numbers for 5 successive numbers see A138985

For Frobenius numbers for 6 successive numbers see A138986

For Frobenius numbers for 7 successive numbers see A138987

For Frobenius numbers for 8 successive numbers see A138988

LINKS

Table of n, a(n) for n=1..59.

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

FORMULA

G.f.: x*(x^12-7*x^6-x^5-x^4-x^3-x^2-x-1) / ((x-1)^3*(x+1)^2*(x^2-x+1)^2*(x^2+x+1)^2). [Colin Barker, Dec 13 2012]

EXAMPLE

a(7) = 15 because 15 is the biggest number k such that equation 8*x_1 + 9*x_2 + 10*x_3 + 11*x_4 + 12*x_5 + 13*x_6 + 14*x_7 = k has no solution for any nonnegative x_i (in other words for every k>15 there exists one or more solutions).

MATHEMATICA

Table[FrobeniusNumber[{n+1, n+2, n+3, n+4, n+5, n+6, n+7}], {n, 1, 100}]

CROSSREFS

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

Sequence in context: A065637 A325805 A039061 * A318534 A265405 A171610

Adjacent sequences:  A138984 A138985 A138986 * A138988 A138989 A138990

KEYWORD

nonn,easy

AUTHOR

Artur Jasinski, Apr 05 2008

STATUS

approved

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Last modified November 22 00:32 EST 2019. Contains 329383 sequences. (Running on oeis4.)