Numbers k such that sigma(k-2) + sigma(k+2) = sigma(2k).

Terms

a(0) =4a(1) =16a(2) =272a(3) =284a(4) =604a(5) =4556a(6) =6904a(7) =8413a(8) =10463a(9) =12070a(10) =19004a(11) =23290a(12) =26284a(13) =29944a(14) =40312a(15) =44252a(16) =107557a(17) =114616a(18) =230987a(19) =239134a(20) =276476a(21) =332022a(22) =343793a(23) =403196a(24) =501008a(25) =762078a(26) =771130a(27) =893606a(28) =1013348a(29) =1160192