Number of ways to pair up {1^2, 2^2, ..., (2n)^2 } so sum of each pair is prime.

A000348

Number of ways to pair up {1^2, 2^2, ..., (2n)^2 } so sum of each pair is prime.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =12a(5) =9a(6) =72a(7) =160a(8) =428a(9) =2434a(10) =3011a(11) =10337a(12) =126962a(13) =264182a(14) =783550a(15) =5004266a(16) =34340141a(17) =176302123a(18) =1188146567a(19) =4457147441a(20) =7845512385a(21) =132253267889

External references