Numbers n such that sigma(sigma(n)) = sigma(sigma(n)-n) + sigma(n); that is, f(g(n)) = g(f(n)) where f = A000203 and g = A001065.

A291881

Numbers n such that sigma(sigma(n)) = sigma(sigma(n)-n) + sigma(n); that is, f(g(n)) = g(f(n)) where f = A000203 and g = A001065.

Terms

    a(0) =2a(1) =38040a(2) =51888a(3) =236644a(4) =260880a(5) =3097024a(6) =5283852a(7) =5667312a(8) =11777472a(9) =46120848a(10) =52981252a(11) =69128640a(12) =121352208a(13) =330364848a(14) =485906400a(15) =662736600a(16) =769422720a(17) =1111869360a(18) =1267978320a(19) =1272335760a(20) =1426817904a(21) =1807128528a(22) =2107406448a(23) =2381691312a(24) =2452404544a(25) =2691587568

External references