A302935 Unitary highly composite deficient numbers: unitary deficient numbers k whose number of unitary divisors ud(k) > ud(m) for all unitary deficient numbers m < k.

1, 2, 10, 84, 1155, 25740, 471240, 14549535, 535422888

Offset: 1

Author

Amiram Eldar, Apr 16 2018

Keywords

• nonn
• more

Comments

The record numbers of unitary divisors are 1, 2, 4, 8, 16, 32, 64, 128, 256, ...

The unitary version of A302934.

Crossrefs

Cf. A034444, A034448, A129487, A302934.

Programs

Mathematica

usigma[n_] := If[n == 1, 1, Times @@ (1 + Power @@@ FactorInteger[n])]; udiv[n_] := 2^PrimeNu[n]; dm = 0; Do[sig = usigma[n]; If[sig >= 2 n, Continue[]]; d = udiv[n]; If[d > dm, Print[n]; dm = d], {n, 1, 1000000000}]

PARI

nbud(n) = 1< maxd), print1(n, ", "); maxd = nbud(n);););} \\ Michel Marcus, Apr 17 2018