OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Vincenzo Librandi)
EXAMPLE
19-1 = 2*3*3 has 3 factors. 19+1 = 2*2*5 has 3 factors. So 19 is in the table.
MAPLE
isA115103 := proc(n)
if not type(n, prime) then
return false;
end if;
if numtheory[bigomega](n-1) <> numtheory[bigomega](n+1) then
false;
else
true ;
end if ;
end proc:
for n from 2 to 3000 do
if isA115103(n) then
printf("%d, ", n) ;
end if;
end do: # R. J. Mathar, Feb 13 2019
# second Maple program:
q:= p-> isprime(p) and (f-> f(p+1)=f(p-1))(numtheory[bigomega]):
select(q, [$1..3000])[]; # Alois P. Heinz, May 08 2022
MATHEMATICA
Select[Prime[Range[400]], PrimeOmega[#-1]==PrimeOmega[#+1]&] (* Harvey P. Dale, Apr 26 2014 *)
PROG
(PARI) g(n) = forprime(x=1, n, p1=bigomega(x-1); p2=bigomega(x+1); if(p1==p2, print1(x", ")))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Mar 02 2006
STATUS
approved