A253610 Numbers n with property that the sum of n and the digital root of n is prime.

1, 10, 11, 13, 14, 16, 28, 29, 32, 34, 35, 46, 49, 52, 53, 65, 67, 68, 71, 82, 85, 89, 100, 101, 103, 104, 106, 122, 124, 136, 137, 142, 143, 155, 158, 160, 172, 175, 176, 190, 191, 193, 194, 209, 215, 226, 227, 229, 232, 233, 247, 250, 262, 265, 266, 269, 280

Offset

1,2

Comments

Indices of primes in A064806. - Tom Edgar, Jan 07 2015

For any prime p >= 11, if p == k mod 9 then n = p - k/2 (if k is even) or p - (k+9)/2 (if k is odd) is in the sequence. - Robert Israel, Jan 07 2015

Links

Table of n, a(n) for n=1..57.

Maple

map(p -> p - (p/2 mod 9), [2, seq(ithprime(i), i=5..100)]); # Robert Israel, Jan 07 2015

Mathematica

Select[Range[100], PrimeQ[#+Mod[#, 9]]&] (* Ivan N. Ianakiev, Feb 01 2015 *)

Prog

(Sage) [n for n in [1..200] if is_prime(n+(1+(n-1)%9))] # Tom Edgar, Jan 05 2015
(Magma) [n: n in [1..300]| IsPrime(n+(1+(n-1)mod 9))]; // Vincenzo Librandi, Jan 15 2015

Crossrefs

Cf. A010888, A064806.

Sequence in context: A339076 A107741 A047791 * A302578 A093679 A153194

Adjacent sequences: A253607 A253608 A253609 * A253611 A253612 A253613

Keyword

nonn,base

Author

Robert Gelhar, Jan 05 2015

Status

approved