Number of mutual-visibility sets in the n X 3 grid graph.

Terms

a(0) =7a(1) =41a(2) =190a(3) =678a(4) =2006a(5) =5130a(6) =11680a(7) =24224a(8) =46576a(9) =84148a(10) =144346a(11) =237010a(12) =374898a(13) =574214a(14) =855180a(15) =1242652a(16) =1766780a(17) =2463712a(18) =3376342a(19) =4555102a(20) =6058798a(21) =7955490a(22) =10323416a(23) =13251960a(24) =16842664a(25) =21210284a(26) =26483890a(27) =32808010a(28) =40343818a(29) =49270366