Number of ways to place 3 points on a triangular grid of side n so that no two of them are adjacent.

A239569

Number of ways to place 3 points on a triangular grid of side n so that no two of them are adjacent.

Terms

    a(0) =0a(1) =1a(2) =21a(3) =151a(4) =615a(5) =1845a(6) =4571a(7) =9926a(8) =19566a(9) =35805a(10) =61765a(11) =101541a(12) =160381a(13) =244881a(14) =363195a(15) =525260a(16) =743036a(17) =1030761a(18) =1405221a(19) =1886035a(20) =2495955a(21) =3261181a(22) =4211691a(23) =5381586a(24) =6809450a(25) =8538725a(26) =10618101a(27) =13101921a(28) =16050601a(29) =19531065

External references