A392260 Numbers k such that sigma(k) = psi(k) + pi(k) + omega(k)^10.

1, 16, 19197, 78669, 197896, 571875885, 1661334225

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Example

19197 is a term since sigma(19197) = 29120 = 25920 + 2176 + 2^10 = psi(19197) + pi(19197) + omega(19197)^10.

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)^10, print1(k, ", "))); q = p); } \\ Amiram Eldar, Feb 06 2026

Crossrefs

Cf. A000203, A000720, A001615, A001221, A390234, A390235, A390236, A392053, A392054, A392909, A393090, A393091. A393094.

Sequence in context: A214637 A288957 A159387 * A283720 A349891 A098175

Adjacent sequences: A392257 A392258 A392259 * A392261 A392262 A392263

Keyword

nonn,hard,more

Author

S. I. Dimitrov, Feb 06 2026

Extensions

a(6)-a(7) from Amiram Eldar, Feb 06 2026

Status

approved