A394751 Numbers k such that sigma(k) = psi(k) + tau(k) + Omega(k)^4.

5375, 13650, 66066, 157794, 197106, 288834, 397535, 459186, 524706, 747474, 917826, 1009554, 1206114, 1533714, 1900626, 2031666, 2450994, 2752386, 2909634, 3407586, 3761394, 4324866, 5137314, 5569746, 5792514, 6251154, 6487026, 6971874, 8806434, 9369906, 10247874, 10549266, 12121746, 12449346

Offset

1,1

Links

Table of n, a(n) for n=1..34.

Example

5375 is a term since sigma(5375) = 6864 = 6600 + 8 + 4^4 = psi(5375) + tau(5375) + Omega(5375)^4.

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)) + numdiv(f) + bigomega(f)^4; } \\ Amiram Eldar, Mar 31 2026

Crossrefs

Cf. A000005, A000203, A001615, A001222, A394658, A394738.

Sequence in context: A258074 A237295 A296146 * A063408 A057850 A058325

Adjacent sequences: A394748 A394749 A394750 * A394753 A394754 A394755

Keyword

nonn

Author

S. I. Dimitrov, Mar 31 2026

Status

approved