cp's OEIS Frontend

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.

A119449 Primes with even digit sum.

Original entry on oeis.org

2, 11, 13, 17, 19, 31, 37, 53, 59, 71, 73, 79, 97, 101, 103, 107, 109, 127, 149, 163, 167, 181, 211, 233, 239, 251, 257, 271, 277, 293, 307, 347, 349, 367, 383, 389, 419, 431, 433, 439, 457, 479, 491, 499, 503, 509, 521, 523, 541, 547, 563, 569, 587, 613, 617
Offset: 1

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Author

Zak Seidov, May 20 2006

Keywords

Comments

On average, there are as many prime numbers for which the sum of decimal digits is even as prime numbers for which it is odd [A119450]. This hypothesis, first made in 1968, has recently been proved by researchers from the Institut de Mathematiques de Luminy. - Jonathan Vos Post, May 13 2010
Also primes such that absolute value of difference between largest digit and the sum of all the other digits is an even integer. This is in accordance with hypothesis of Alexandre Gelfond, proved by C. Mauduit and J. Rivat, see the link below. - Osama Abuajamieh, Feb 10 2017.

Crossrefs

Intersection of A054683 and A000040.
Primes with odd digit sum A119450.

Programs

  • Mathematica
    Select[Prime@ Range@ 113, EvenQ@ Total@ IntegerDigits@ # &] (* Michael De Vlieger, Feb 11 2017 *)
  • PARI
    isok(n) = isprime(n) && (sumdigits(n) % 2 == 0); \\ Michel Marcus, Oct 10 2013