A209875 Primes p such that p and p+18 are consecutive primes with equal digital sum.

523, 1069, 1259, 1759, 1913, 2503, 3803, 4159, 4373, 4423, 4463, 4603, 4703, 4733, 5059, 5209, 6229, 6529, 6619, 7159, 7433, 7459, 8191, 9109, 9749, 9949, 10691, 10753, 12619, 12763, 12923, 13763, 14033, 14303, 14369, 15859, 15973, 16529, 16673, 16903, 17239, 17359

Offset: 1

Author

Antonio Roldán, Mar 14 2012

Keywords

• nonn
• base
• less

Comments

Subsequence of A066540 and A209663 (A066540 contains some consecutive primes with differences greater than 18; A209663 allows nonconsecutive primes).

Examples

			19013 is in the sequence because 19013 is prime, 19013 + 18 = 19031 is the next prime, and sum_of_digits(19013) = sum_of_digits(19031) = 14.
		

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000 (terms 1..2999 from R. J. Mathar)

Crossrefs

Cf. A066540, A209663.

Programs

PARI

{forprime(n=3, 20000, my(m=nextprime(n+1)); if(m-n==18 && sumdigits(n) == sumdigits(m), print1(n, ", ")))} \\ Antonio Roldán, Dec 21 2012

Extensions

"Correction" of early 2012 undone by R. J. Mathar, Feb 20 2023