login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108606 Semiprimes with prime sum of digits. 3
14, 21, 25, 34, 38, 49, 58, 65, 74, 85, 94, 106, 111, 115, 119, 122, 133, 142, 146, 155, 166, 201, 203, 205, 209, 214, 218, 221, 247, 254, 265, 274, 278, 287, 289, 298, 302, 319, 326, 335, 346, 355, 362, 371, 377, 382, 386, 391, 395, 403, 407, 427, 445, 454 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

34 is the smallest term in common with A108605. Cf. A001358 semiprimes, A101605 3-almost primes, A108605 semiprimes with prime sum of factors, A108607 intersection of A108605 and A108606.

LINKS

Table of n, a(n) for n=1..54.

EXAMPLE

34=2*17 (semiprime) and 2+17=19 is prime.

MATHEMATICA

A108606=Select[Range[1000], Plus@@(Transpose[FactorInteger[ # ]])[[2]]==2&& PrimeQ[Plus@@IntegerDigits[ # ]]&]

CROSSREFS

Cf. A001358, A101605, A108606, A108607.

Sequence in context: A234802 A162780 A002410 * A129497 A255742 A093994

Adjacent sequences:  A108603 A108604 A108605 * A108607 A108608 A108609

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Jun 12 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 10:49 EDT 2019. Contains 327229 sequences. (Running on oeis4.)