A070028 Absolute primes: primes whose initial, all intermediate and final sums of digits are primes.

2, 3, 5, 7, 11, 113, 131, 311, 11111111111111111111111

Offset

1,1

Comments

The next terms are R(317) and R(1031) where R(n)=(10^n-1)/9 is a repunit prime. This sequence is a subsequence of A003459 and A070027.

Links

Table of n, a(n) for n=1..9.

Example

113 is a term because 113 and permutations 131 and 311 are prime as is 1+1+3=5. 11111111111111111111111 is a term because it is prime, all permutations of its digits are prime, the sum of its digits, 23, is prime and 2+3=5 is also prime.

Crossrefs

Cf. A003459 (absolute primes), A004022 (repunit primes), A070027.

Sequence in context: A033938 A069598 A049575 * A084836 A062351 A185267

Adjacent sequences: A070025 A070026 A070027 * A070029 A070030 A070031

Keyword

base,nonn

Author

Rick L. Shepherd, Apr 15 2002

Status

approved