A354103 a(n) = sigma(A267099(n)), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes, and sigma is the sum of divisors function.

1, 3, 6, 7, 4, 18, 14, 15, 31, 12, 18, 42, 8, 42, 24, 31, 12, 93, 30, 28, 84, 54, 38, 90, 13, 24, 156, 98, 20, 72, 42, 63, 108, 36, 56, 217, 24, 90, 48, 60, 32, 252, 54, 126, 124, 114, 62, 186, 183, 39, 72, 56, 44, 468, 72, 210, 180, 60, 74, 168, 48, 126, 434, 127, 32, 324, 90, 84, 228, 168, 98, 465, 60, 72, 78, 210

Offset: 1

Author

Antti Karttunen, May 18 2022

Keywords

• nonn
• mult

Links

• Antti Karttunen, Table of n, a(n) for n = 1..19683

Crossrefs

Inverse Möbius transform of A267099.

Cf. A000203, A354102.

Programs

PARI

A354103(n) = sigma(A267099(n)); \\ Uses the program given in A267099.

Formula

a(n) = A000203(A267099(n)).

a(n) = Sum_{d|n} A267099(d).