

A357780


Primes p such that changing, in p, all 1's to 2's we get semiprimes and changing all 1's to 3's we get triprimes.


0



61, 199, 313, 421, 619, 661, 1033, 1163, 1217, 1283, 1301, 1361, 1567, 1613, 1721, 1723, 1759, 1987, 2179, 2341, 2617, 3011, 3163, 3217, 4211, 4519, 4621, 5107, 7417, 8117, 8123, 8317, 8521, 9199, 9319, 9721, 9817, 10037, 10093, 10099, 10139, 10163, 10211, 10243, 10567, 10589, 10601, 10687, 10781, 10837, 10957
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OFFSET

1,1


LINKS



EXAMPLE

1217 (prime), 2227 = 17*131 (semiprime), 3237 = 3*13*83 (triprime).


MATHEMATICA

s = {}; p = 2; Do[ p = NextPrime[p]; id = IntegerDigits[p]; id2 = id3 = id;
Do[If[id[[k]] == 1, id2[[k]] = 2; id3[[k]] = 3], {k, Length[id]}]; fd2 = FromDigits[id2]; fd3 = FromDigits[id3]; If[2 == PrimeOmega[fd2] && 3 == PrimeOmega[fd3], AppendTo[s, p]], {2000}]; s


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



