Number of mutual-visibility sets in the n X 4 grid graph.

Terms

a(0) =11a(1) =94a(2) =678a(3) =3771a(4) =16724a(5) =61382a(6) =192280a(7) =528267a(8) =1302956a(9) =2940272a(10) =6162266a(11) =12137259a(12) =22677276a(13) =40494626a(14) =69528380a(15) =115352395a(16) =185677428a(17) =290960780a(18) =445137806a(19) =666490523a(20) =978669444a(21) =1411885662a(22) =2004291104a(23) =2803565771a(24) =3868731676a(25) =5272214088a(26) =7102171586a(27) =9465117323