A138993 a(n) = Frobenius number for 7 successive primes = F[p(n), p(n+1), p(n+2), p(n+3), p(n+4), p(n+5), p(n+6)].

1, 4, 9, 16, 27, 41, 49, 63, 102, 114, 169, 187, 203, 221, 304, 328, 409, 441, 465, 495, 525, 559, 769, 811, 867, 907, 826, 854, 886, 938, 1403, 1451, 1505, 1555, 1786, 1838, 1741, 2125, 2193, 2605, 2325, 2005, 2479, 2318, 2362, 2637, 3402, 4012, 3857, 3666

Offset

1,2

Links

Table of n, a(n) for n=1..50.

Example

a(4)=16 because 16 is the largest number k such that the equation 7*x_1 + 11*x_2 + 13*x_3 + 17*x_4 + 19*x_5 + 23*x_6 + 29*x_7 = k has no solution for any nonnegative x_i (in other words, for every k > 16 there exist one or more solutions).

Mathematica

Table[FrobeniusNumber[{Prime[n], Prime[n + 1], Prime[n + 2], Prime[n + 3], Prime[n + 4], Prime[n + 5], Prime[n + 6]}], {n, 1, 100}]
FrobeniusNumber/@Partition[Prime[Range[100]], 7, 1] (* Harvey P. Dale, Aug 15 2014 *)

Crossrefs

Frobenius numbers for k successive primes: A037165 (k=2), A138989 (k=3), A138990 (k=4), A138991 (k=5), A138992 (k=6), this sequence (k=7), A138994 (k=8).

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

Sequence in context: A109593 A237589 A138981 * A339330 A008019 A029896

Adjacent sequences: A138990 A138991 A138992 * A138994 A138995 A138996

Keyword

nonn

Author

Artur Jasinski, Apr 05 2008

Status

approved