OFFSET
1,1
COMMENTS
a(n) is the least number k > a(n-1) such that k, k - a(n-1), and k + a(n-1) are all in A014613.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 100 because a(2) = 40 and 100 = 2^2 * 5^2, 100 - 40 = 60 = 2^2 * 3 * 5 and 100 + 40 = 140 = 2^2 * 4 * 7 are all in A014613.
MAPLE
isA014613:= proc(n) option remember; numtheory:-bigomega(n) = 4 end proc:
R:= 16: a:= 16: count:= 1:
while count < 100 do
for x from a+16 do
if isA014613(x-a) and isA014613(x) and isA014613(x+a) then break fi
od;
R:= R, x; a:= x; count:= count+1;
od:
R;
MATHEMATICA
s = {m = 16}; Do[p = m + 16; While[{4, 4, 4} != PrimeOmega[{p, m +
p, p - m}], p++]; AppendTo[s, m = p], {50}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert Israel, Dec 11 2023
STATUS
approved