a(n) is the number of quadruples (a_1, a_2, a_3, a_4) having all terms in {1,...,n} such that there exists a quadrilateral with these side lengths.
A346636
a(n) is the number of quadruples (a_1, a_2, a_3, a_4) having all terms in {1,...,n} such that there exists a quadrilateral with these side lengths.
Terms
- a(0) =0a(1) =1a(2) =16a(3) =77a(4) =236a(5) =565a(6) =1156a(7) =2121a(8) =3592a(9) =5721a(10) =8680a(11) =12661a(12) =17876a(13) =24557a(14) =32956a(15) =43345a(16) =56016a(17) =71281a(18) =89472a(19) =110941a(20) =136060a(21) =165221a(22) =198836a(23) =237337a(24) =281176a(25) =330825a(26) =386776a(27) =449541a(28) =519652a(29) =597661
External references
- oeis: A346636