A394403 Numbers k such that sigma(k) = psi(k) + pi(k) + Omega(k)^8.

1, 276543, 73296375, 274611750, 9076584475, 25403983825

Offset

1,2

Links

Table of n, a(n) for n=1..6.

Example

276543 is a term since sigma(276543) = 399464 = 368736 + 24167 + 3^8 = psi(276543) + pi(276543) + Omega(276543)^8.

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 + bigomega(f)^8, print1(k, ", "))); q = p); } \\ Amiram Eldar, Mar 19 2026

Crossrefs

Cf. A000203, A000720, A001615, A001222, A393162, A393163, A393123, A394260, A394312, A394315, A394402.

Sequence in context: A069372 A157839 A237808 * A271349 A295472 A162765

Adjacent sequences: A394400 A394401 A394402 * A394404 A394405 A394406

Keyword

nonn,hard,more

Author

S. I. Dimitrov, Mar 19 2026

Extensions

a(5)-a(6) from Amiram Eldar, Mar 20 2026

Status

approved