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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

User: Robert Gelhar

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Robert Gelhar has authored 1 sequences.

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

Original entry on oeis.org

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

Author

Robert Gelhar, Jan 05 2015

Keywords

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

Crossrefs

Programs

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