Variant of A095236, where first two people choose payphones at the ends.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =4a(5) =16a(6) =32a(7) =48a(8) =96a(9) =384a(10) =3072a(11) =9216a(12) =36864a(13) =46080a(14) =184320a(15) =483840a(16) =3870720a(17) =7741440a(18) =82575360a(19) =743178240a(20) =23781703680a(21) =59454259200a(22) =475634073600