OFFSET
1,1
COMMENTS
All terms == 1 or 2 (mod 8).
One of the numbers k, k+1, ..., k+5 is a Zumkeller number (A083207), since it is of the form 2*3*p, where p is prime > 3. - Ivan N. Ianakiev, Aug 08 2024
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 18241 is a term because
18241 = 17 * 29 * 37
18242 = 2 * 7 * 1303
18243 = 3^2 * 2027
18244 = 2^2 * 4561
18245 = 5 * 41 * 89
18246 = 2 * 3 * 3041
are all products of 3 primes (counted with multiplicity).
MAPLE
R:= NULL: count:= 0: p:= 1:
while count < 100 do
p:= nextprime(p);
x:= 4*p;
if andmap(t -> numtheory:-bigomega(t)=3, [x-2, x-1, x+1, x+2]) then
if numtheory:-bigomega(x-3) = 3 then R:= R, x-3; count:= count+1; fi;
if numtheory:-bigomega(x+3) = 3 then R:= R, x-2; count:= count+1; fi;
fi;
od:
R;
MATHEMATICA
s = {}; Do[If[{3, 3, 3, 3, 3, 3} == PrimeOmega[Range[k, k + 5]],
AppendTo[s, k]], {k, 1000000}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert Israel, Aug 06 2024
STATUS
approved