A392909 Numbers k such that sigma(k) = psi(k) + pi(k) + omega(k)^6.

1, 16, 344, 5396, 28683, 28719, 55719, 94941, 34872550, 401229975, 656640625

Offset

1,2

Links

Table of n, a(n) for n=1..11.

Example

344 is a term since sigma(344) = 660 = 528 + 68 + 2^6 = psi(344) + pi(344) + omega(344)^6.

Prog

(PARI) dedpsi(f) = prod(k = 1, #f~, (f[k, 1]+1) * f[k, 1]^(f[k, 2]-1));
list(lim) = {my(q = 2, m = 0, f); print1(1, ", "); forprime(p = 3, lim, m++; for(k = q, p-1, f = factor(k); if(sigma(f) == dedpsi(f) + m + omega(f)^6, print1(k, ", "))); q = p); } \\ Amiram Eldar, Jan 26 2026

Crossrefs

Cf. A000203, A000720, A001615, A001221, A390234, A390235, A390236, A392053, A392054.

Sequence in context: A173906 A386899 A227102 * A221577 A363383 A384169

Adjacent sequences: A392906 A392907 A392908 * A392910 A392911 A392912

Keyword

nonn,hard,more

Author

S. I. Dimitrov, Jan 26 2026

Extensions

a(10)-a(11) from Amiram Eldar, Jan 26 2026

Status

approved