Number of upward triangles in a Star of David matchstick arrangement of size n.

Terms

a(0) =0a(1) =10a(2) =59a(3) =177a(4) =394a(5) =740a(6) =1245a(7) =1939a(8) =2852a(9) =4014a(10) =5455a(11) =7205a(12) =9294a(13) =11752a(14) =14609a(15) =17895a(16) =21640a(17) =25874a(18) =30627a(19) =35929a(20) =41810a(21) =48300a(22) =55429a(23) =63227a(24) =71724a(25) =80950a(26) =90935a(27) =101709a(28) =113302a(29) =125744