Number of edges in a "frame" of size n X n (see Comments in A331776 for definition).

Terms

a(0) =8a(1) =92a(2) =360a(3) =860a(4) =1792a(5) =3124a(6) =5256a(7) =8188a(8) =12304a(9) =17460a(10) =24568a(11) =33244a(12) =44688a(13) =58228a(14) =74664a(15) =94028a(16) =118080a(17) =145380a(18) =178568a(19) =216252a(20) =259776a(21) =308276a(22) =365352a(23) =428556a(24) =501152a(25) =580804a(26) =670536a(27) =768908a(28) =880992a(29) =1001764