login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A138984 a(n) = Frobenius number for 4 successive numbers = F(n+1,n+2,n+3,n+4). 7
1, 2, 3, 9, 11, 13, 23, 26, 29, 43, 47, 51, 69, 74, 79, 101, 107, 113, 139, 146, 153, 183, 191, 199, 233, 242, 251, 289, 299, 309, 351, 362, 373, 419, 431, 443, 493, 506, 519, 573, 587, 601, 659, 674, 689, 751, 767, 783, 849, 866, 883, 953, 971, 989, 1063, 1082 (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..56.

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

FORMULA

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

EXAMPLE

a(4) = 9 because 9 is the biggest number k such that equation: 5*x_1+6*x_2+7*x_3+9*x_4 = k has no solution for any nonnegative x_i (in other words for every k>9 there exists one or more solutions)

MATHEMATICA

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

CROSSREFS

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

Sequence in context: A140222 A272537 A121557 * A110772 A074338 A111319

Adjacent sequences:  A138981 A138982 A138983 * A138985 A138986 A138987

KEYWORD

nonn,easy

AUTHOR

Artur Jasinski, Apr 05 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 7 03:00 EST 2019. Contains 329836 sequences. (Running on oeis4.)