A393667 Numbers k such that sigma(k) = psi(k) + phi(k) + Omega(k)^9.

68775252, 99370068, 100941852, 103099164, 111338916, 152835592, 184062876, 204386268, 204787644, 213055356, 214257972, 223533708, 232198716, 238059636, 238753236, 240521916, 248428956, 248671716, 248983836, 249802420, 270388552, 276297468, 328026828, 330511332, 337948660, 359289132

Offset

1,1

Links

Michael S. Branicky, Table of n, a(n) for n = 1..45

Example

68775252 is a term since sigma(68775252) = 197511552 = 169295616 + 18138240 + 6^9 = psi(68775252) + phi(68775252) + Omega(68775252)^9.

Prog

(PARI) isok(k) = {my(f = factor(k)); sigma(f) == prod(i=1, #f~, (f[i, 1]+1) * f[i, 1]^(f[i, 2]-1)) + eulerphi(f) + bigomega(f)^9; } \\ Amiram Eldar, Feb 24 2026

Crossrefs

Cf. A000203, A001615, A000010, A001222, A390049, A393229, A393230, A393425, A391448, A393528, A393529, A393666.

Sequence in context: A084071 A251615 A321706 * A388027 A172608 A294989

Adjacent sequences: A393664 A393665 A393666 * A393668 A393669 A393670

Keyword

nonn

Author

S. I. Dimitrov, Feb 24 2026

Extensions

More terms from Amiram Eldar, Feb 24 2026

Status

approved