Palindromes of form k*(k+4).

Terms

a(0) =0a(1) =5a(2) =77a(3) =252a(4) =525a(5) =1221a(6) =2112a(7) =21312a(8) =56165a(9) =73437a(10) =276672a(11) =1265621a(12) =2114112a(13) =2509052a(14) =29311392a(15) =69555596a(16) =71588517a(17) =122434221a(18) =126000621a(19) =540888045a(20) =5401221045a(21) =21183638112a(22) =69069096096a(23) =71149694117a(24) =79158385197