OFFSET
1,1
COMMENTS
Note that 137 and 139 are twin primes.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
2+9=11=prime for 29 and 5+8=13=prime for 58=2*29;
1+3+7=11=prime for 137 and 2+7+4=13=prime for 274=2*137;
1+3+9=13=prime for 139 and 2+7+8=17=prime for 278=2*139.
MAPLE
filter:= proc(n)
isprime(n) and isprime(convert(convert(n, base, 10), `+`)) and isprime(convert(convert(2*n, base, 10), `+`))
end proc:
select(filter, [seq(i, i=3..5000, 2)]); # Robert Israel, Sep 04 2019
MATHEMATICA
Select[Prime[Range[300]], And@@PrimeQ[Total/@{IntegerDigits[#], IntegerDigits[2 #]}]&] (* Harvey P. Dale, Jun 26 2011 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Patrick Capelle, Jun 20 2003
EXTENSIONS
More terms from Reinhard Zumkeller, Jun 26 2003
Offset changed to 1 by Robert Israel, Sep 04 2019
STATUS
approved