A069758 Frobenius number of the numerical semigroup generated by three consecutive hexagonal numbers.

65, 377, 395, 797, 1589, 6029, 3347, 4571, 6035, 10997, 10979, 12212, 19409, 47246, 24023, 29003, 35357, 52112, 50603, 50411, 73049, 158207, 78155, 90203, 102005, 144443, 138467, 131474, 183077

Offset: 2

Author

Victoria A Sapko (vsapko(AT)canes.gsw.edu), Apr 08 2002

Keywords

• easy
• nonn

Comments

The Frobenius number of a numerical semigroup generated by relatively prime integers a_1,...,a_n is the largest positive integer that is not a nonnegative linear combination of a_1,...,a_n. Since three consecutive hexagonal numbers are relatively prime, they generate a numerical semigroup with a Frobenius number.

Examples

			a(2)=65 because 65 is not a nonnegative linear combination of 6, 15 and 28, but all integers greater than 65 are.
		

Links

• R. Fröberg, C. Gottlieb and R. Häggkvist, On numerical semigroups, Semigroup Forum, 35 (1987), 63-83 (for definition of Frobenius number).

Crossrefs

Cf. A000384, A037165, A059769, A069755-A069764.

Programs

Mathematica

FrobeniusNumber/@Partition[Table[n(2n-1),{n,2,35}],3,1] (* Harvey P. Dale, Jul 25 2011 *)