Number of mutual-visibility sets in the n-ladder graph.

Terms

a(0) =4a(1) =15a(2) =41a(3) =94a(4) =190a(5) =349a(6) =595a(7) =956a(8) =1464a(9) =2155a(10) =3069a(11) =4250a(12) =5746a(13) =7609a(14) =9895a(15) =12664a(16) =15980a(17) =19911a(18) =24529a(19) =29910a(20) =36134a(21) =43285a(22) =51451a(23) =60724a(24) =71200a(25) =82979a(26) =96165a(27) =110866a(28) =127194a(29) =145265