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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A118721 Chen primes for which the sum of the digits is also a Chen prime. 1
2, 3, 5, 7, 11, 23, 29, 41, 47, 67, 83, 89, 101, 113, 131, 137, 139, 157, 179, 191, 197, 199, 227, 263, 269, 281, 311, 317, 337, 353, 359, 379, 401, 409, 443, 449, 461, 467, 487, 557, 571, 577, 599, 641, 647, 683, 719, 751, 797, 809, 821, 827, 829, 863, 881 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

29 is in the sequence because (1) it is a Chen prime and (2) the sum of its digits 2+9=11 is also a Chen prime.

MATHEMATICA

With[{ch=Select[Prime[Range[200]], PrimeOmega[#+2]<3&]}, Select[ch, MemberQ[ ch, Total[IntegerDigits[#]]]&]] (* Harvey P. Dale, May 10 2018 *)

CROSSREFS

Cf. A109611.

Sequence in context: A207294 A156658 A118723 * A094318 A019344 A229291

Adjacent sequences:  A118718 A118719 A118720 * A118722 A118723 A118724

KEYWORD

base,nonn

AUTHOR

Luc Stevens (lms022(AT)yahoo.com), May 21 2006

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 March 19 19:30 EDT 2019. Contains 321330 sequences. (Running on oeis4.)