OFFSET
1,1
COMMENTS
EXAMPLE
tau(421) = 2, tau (422) = 4, tau (423) = 6, tau (424) = 8.
MATHEMATICA
Select[Range[10^6], DivisorSigma[0, # + {0, 1, 2, 3}] == {2, 4, 6, 8} &] (* Amiram Eldar, Jan 25 2021 *)
Select[Prime[Range[490000]], DivisorSigma[0, #+{1, 2, 3}]=={4, 6, 8}&] (* Harvey P. Dale, Oct 02 2021 *)
PROG
(Magma) [m: m in [1..10^7] | IsPrime(m) and #Divisors(m + 1) eq 4 and #Divisors(m + 2) eq 6 and #Divisors(m + 3) eq 8]
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 24 2021
STATUS
approved