

A335496


a(n) is the least odd number k such that Omega(k) = n, Omega(k+2) = n+1, and Omega(k+4) = n+2, where Omega(k) is the number of prime factors of k (A001222).


1




OFFSET

1,1


COMMENTS

a(n) (mod 81) for n=1..8: {23, 61, 77, 77, 77, 77, 77, 0}.


LINKS

Table of n, a(n) for n=1..8.


EXAMPLE

23 (prime), 25=5*5 (semiprime),27=3*3*3 (3almost prime);
871 = 13*67 (semiprime),
873 = 3*3*97 (3almost prime),
875 = 5*5*5*7 (4almost prime).


CROSSREFS

Sequence in context: A158505 A217116 A081731 * A183523 A233339 A008961
Adjacent sequences: A335493 A335494 A335495 * A335497 A335498 A335499


KEYWORD

nonn,more


AUTHOR

Zak Seidov and Giovanni Resta, Jun 11 2020


STATUS

approved



