A118721 Chen primes for which the sum of the digits is also a Chen prime.

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

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