OFFSET
1,1
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..10000
EXAMPLE
a(2) = 4: 4*prime(4) + (4+1)*prime(4+1) + (4+2)*prime(4+2) = 161 = 7 * 23 is semiprime.
a(5) = 9: 9*prime(9) + (9+1)*prime(9+1) + (9+2)*prime(9+2) = 838 = 2 * 419 is semiprime.
MAPLE
MATHEMATICA
c = 0; Do[If[PrimeOmega[n*Prime[n] + (n+1)*Prime[n+1] + (n+2)*Prime[n+2]]==2, c++; Print[c, " ", n]], {n, 1, 85000}];
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, May 27 2014
STATUS
approved