Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #8 Feb 10 2021 08:11:14
%S 65,377,395,797,1589,6029,3347,4571,6035,10997,10979,12212,19409,
%T 47246,24023,29003,35357,52112,50603,50411,73049,158207,78155,90203,
%U 102005,144443,138467,131474,183077
%N Frobenius number of the numerical semigroup generated by three consecutive hexagonal numbers.
%C 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.
%D R. Fröberg, C. Gottlieb and R. Häggkvist, "On numerical semigroups", Semigroup Forum, 35 (1987), 63-83 (for definition of Frobenius number).
%e a(2)=65 because 65 is not a nonnegative linear combination of 6, 15 and 28, but all integers greater than 65 are.
%t FrobeniusNumber/@Partition[Table[n(2n-1),{n,2,35}],3,1] (* _Harvey P. Dale_, Jul 25 2011 *)
%Y Cf. A000384, A037165, A059769, A069755-A069764.
%K easy,nonn
%O 2,1
%A Victoria A Sapko (vsapko(AT)canes.gsw.edu), Apr 08 2002