This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A380442 #37 Aug 11 2025 01:19:12 %S A380442 1,1,3,2,5,7,7,11,13,11,17,19,23,23,29,31,35,39,43,47,51,47,59,63,67, %T A380442 71,79,83,89,95,101,107,113,103,125,131,139,143,153,155,167,175,181, %U A380442 191,199,199,215,223,233,239,251,259,269,279,289,299,309,311,329,339 %N A380442 a(n) is the largest Frobenius number of three distinct relatively prime numbers that sum to n. %C A380442 6 is the smallest number that can be partitioned into three distinct positive integers excluding n = 1 through 5. %C A380442 a(6) would be -1 as the only partition of 6 into 3 distinct numbers that are relatively prime are (1, 2, 3) and the largest Frobenius number of that partition is -1. %C A380442 Similarly a(7) and a(8) would be -1 as all partitions of these numbers into three distinct parts have a 1 in them. %H A380442 Brady Haran and David Eisenbud, <a href="https://www.youtube.com/watch?v=be8BGCLuC54">The Frobenius Problem (and numerical semigroups) - Numberphile</a>, Numberphile video, 2025 %e A380442 a(11) = 3 as the partitions of 11 into 3 distinct numbers that are relatively prime are (2,4,5) and (2,3,6) that have Frobenius number 3 and 1 respectively and their maximum is 3. %Y A380442 Cf. A386243. %K A380442 nonn %O A380442 9,3 %A A380442 _David A. Corneth_, Jul 25 2025