A109981 Primes such that both the sum of digits and the number of digits are primes.

11, 23, 29, 41, 43, 47, 61, 67, 83, 89, 101, 113, 131, 137, 139, 151, 157, 173, 179, 191, 193, 197, 199, 223, 227, 229, 241, 263, 269, 281, 283, 311, 313, 317, 331, 337, 353, 359, 373, 379, 397, 401, 409, 421, 443, 449, 461, 463, 467, 487, 557, 571, 577, 593

Offset

1,1

Comments

Cf. A046704 Additive primes: sum of digits is a prime, A088136 Primes such that sum of first and last digits is prime.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

G. Harman, Counting Primes whose Sum of Digits is Prime, J. Integer Seq., 15 (2012), Article 12.2.2.

Example

a(86) = 10037 because both the sum (=11) and number (=5) of digits are primes.

Mathematica

Select[Prime[Range[200]], PrimeQ[Length[IntegerDigits[ # ]]]&&PrimeQ[Plus@@IntegerDigits[ # ]]&]

Prog

(Haskell)
a109981 n = a109981_list !! (n-1)
a109981_list = filter ((== 1) . a010051' . a055642) a046704_list
-- Reinhard Zumkeller, Nov 16 2012

Crossrefs

Cf. A046704, A088136.

Cf. A010051, A055642.

Sequence in context: A271983 A136000 A054723 * A091367 A088136 A164932

Adjacent sequences: A109978 A109979 A109980 * A109982 A109983 A109984

Keyword

base,nonn

Author

Zak Seidov, Jul 06 2005

Status

approved