Least k such that prime(n)^2 divides binomial(2k,k).

Terms

a(0) =3a(1) =5a(2) =13a(3) =25a(4) =61a(5) =85a(6) =145a(7) =181a(8) =265a(9) =421a(10) =481a(11) =685a(12) =841a(13) =925a(14) =1105a(15) =1405a(16) =1741a(17) =1861a(18) =2245a(19) =2521a(20) =2665a(21) =3121a(22) =3445a(23) =3961a(24) =4705a(25) =5101a(26) =5305a(27) =5725a(28) =5941a(29) =6385