Hosoya triangle of Pell-Lucas type.

Terms

a(0) =4a(1) =12a(2) =12a(3) =28a(4) =36a(5) =28a(6) =68a(7) =84a(8) =84a(9) =68a(10) =164a(11) =204a(12) =196a(13) =204a(14) =164a(15) =396a(16) =492a(17) =476a(18) =476a(19) =492a(20) =396a(21) =956a(22) =1188a(23) =1148a(24) =1156a(25) =1148a(26) =1188a(27) =956a(28) =2308a(29) =2868