Odd numbers k such that abs(sigma(k)-2k) <= sqrt(k). Abundance-radius = abs(sigma(k)-2k) does not exceed square root of k and k is odd.

A087415

Odd numbers k such that abs(sigma(k)-2k) <= sqrt(k). Abundance-radius = abs(sigma(k)-2k) does not exceed square root of k and k is odd.

Terms

    a(0) =1a(1) =315a(2) =945a(3) =1155a(4) =2205a(5) =7425a(6) =8415a(7) =8925a(8) =9405a(9) =9555a(10) =24885a(11) =26145a(12) =26325a(13) =28035a(14) =30555a(15) =31815a(16) =32445a(17) =33705a(18) =34335a(19) =35595a(20) =40005a(21) =40365a(22) =41265a(23) =43155a(24) =46035a(25) =49875a(26) =51765a(27) =55335a(28) =78975a(29) =80535

External references