A138989 a(n) = Frobenius number for 3 successive primes = F[p(n), p(n+1), p(n+2)].

1, 4, 13, 30, 53, 80, 117, 131, 194, 286, 293, 520, 613, 522, 1310, 858, 1001, 929, 1610, 1418, 1322, 1499, 1421, 2941, 3300, 3533, 3710, 3957, 2065, 2241, 3685, 4595, 3697, 3930, 5956, 12074, 5509, 5874, 14690, 7968, 6084, 6373, 12413, 12740, 6694, 21878

Offset

1,2

Links

Table of n, a(n) for n=1..46.

Example

a(3)=13 because 13 is the largest number k such that the equation 5*x_1 + 7*x_2 + 11*x_3 = k has no solution for any nonnegative x_i. (In other words, for every k > 13 there exist one or more solutions.)

Mathematica

Table[FrobeniusNumber[{Prime[n], Prime[n + 1], Prime[n + 2}], {n, 1, 100}]
FrobeniusNumber/@Partition[Prime[Range[50]], 3, 1] (* Harvey P. Dale, Dec 01 2015 *)

Crossrefs

Frobenius numbers for k successive primes: A037165 (k=2), this sequence (k=3), A138990 (k=4), A138991 (k=5), A138992 (k=6), A138993 (k=7), A138994 (k=8).

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

Sequence in context: A264536 A161742 A041301 * A254830 A071400 A206806

Adjacent sequences: A138986 A138987 A138988 * A138990 A138991 A138992

Keyword

nonn

Author

Artur Jasinski, Apr 05 2008

Status

approved