Product of largest prime <= n and smallest prime >= n.

Terms

a(0) =1a(1) =1a(2) =4a(3) =9a(4) =15a(5) =25a(6) =35a(7) =49a(8) =77a(9) =77a(10) =77a(11) =121a(12) =143a(13) =169a(14) =221a(15) =221a(16) =221a(17) =289a(18) =323a(19) =361a(20) =437a(21) =437a(22) =437a(23) =529a(24) =667a(25) =667a(26) =667a(27) =667a(28) =667a(29) =841