Numbers k such that sigma(k) + phi(k) + d(k) = sigma(k+1) + phi(k+1) + d(k+1), where sigma(k) is the sum of the divisors of k, phi(k) the Euler totient function of k and d(k) the number of divisors of k.

A259495

Numbers k such that sigma(k) + phi(k) + d(k) = sigma(k+1) + phi(k+1) + d(k+1), where sigma(k) is the sum of the divisors of k, phi(k) the Euler totient function of k and d(k) the number of divisors of k.

Terms

    a(0) =4a(1) =285a(2) =902a(3) =2013a(4) =8493a(5) =37406a(6) =61918a(7) =90094a(8) =120001a(9) =184484a(10) =250550a(11) =303853a(12) =352941a(13) =360446a(14) =375565a(15) =501693a(16) =724934a(17) =889285a(18) =940093a(19) =995630a(20) =1079662a(21) =1473565a(22) =1488957a(23) =1517206a(24) =1573045a(25) =1581806a(26) =1692302a(27) =1864285a(28) =2048973a(29) =2693517

External references