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A108610
Semiprimes with prime sum of decimal digits and prime sum of prime factors.
1
34, 58, 142, 214, 274, 298, 382, 454, 478, 562, 694, 838, 922, 1042, 1138, 1198, 1282, 1318, 1642, 1714, 2038, 2098, 2122, 2182, 2302, 2458, 2638, 2854, 2902, 2962, 3334, 3394, 3442, 3574, 3754, 3862, 4054, 4162, 4258, 4474, 4618, 4762, 5314, 5374, 5422
OFFSET
1,1
COMMENTS
Intersection of A108605 and A108606. All terms are even. Cf. A001358 semiprimes, A101605 3-almost primes, A108605 semiprimes with prime sum of factors, A108606 semiprimes with prime sum of digits.
LINKS
EXAMPLE
34=2*17 (semiprime), with 3+4=7 and 2+17=19 both prime.
MATHEMATICA
psddQ[n_]:=!IntegerQ[Sqrt[n]]&&PrimeOmega[n]==2&&PrimeQ[Total[ IntegerDigits[n]]] && PrimeQ[Total[Transpose[FactorInteger[n]][[1]]]]; Select[Range[5500], psddQ] (* Harvey P. Dale, Oct 03 2012 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Jun 12 2005
STATUS
approved