a(n) = A353749(sigma(A003961(n))), where A353749(k) = phi(k) * A064989(k), and A064989 shifts the prime factorization one step towards lower primes, while A003961 shifts the factorization one step towards higher primes.
A353790
a(n) = A353749(sigma(A003961(n))), where A353749(k) = phi(k) * A064989(k), and A064989 shifts the prime factorization one step towards lower primes, while A003961 shifts the factorization one step towards higher primes.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =132a(4) =4a(5) =16a(6) =8a(7) =48a(8) =870a(9) =16a(10) =30a(11) =528a(12) =24a(13) =32a(14) =32a(15) =5390a(16) =24a(17) =1740a(18) =16a(19) =528a(20) =96a(21) =120a(22) =48a(23) =384a(24) =1224a(25) =96a(26) =1056a(27) =1056a(28) =16a(29) =128
External references
- oeis: A353790