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.

A118134 Primes p such that 4p is the sum of two consecutive primes.

Original entry on oeis.org

2, 3, 13, 17, 43, 67, 127, 137, 167, 193, 223, 283, 487, 563, 613, 617, 643, 647, 773, 1033, 1187, 1193, 1277, 1427, 1453, 1483, 1543, 1663, 1847, 1949, 2027, 2143, 2297, 2371, 2423, 2437, 2477, 2503, 2609, 2683, 2843, 2857, 2927, 3119, 3137, 3163, 3253, 3433
Offset: 1

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Author

Anton Vrba (antonvrba(AT)yahoo.com), May 13 2006

Keywords

Comments

From Zak Seidov, Jun 18 2016: (Start)
Minimal difference between odd terms is 4.
a(n+1) - a(n) = 4 for n = {3, 15, 17, 147, 209, 277, 414, 422, 495, 825, 1053, 1380, 1504, 2078, 2264, 2375, 2605, 4224, 4495, 5180, 5825, 6497, 7107, 7372, 8951} and a(n) = {13, 613, 643, 16183, 24763, 37993, 63853, 65323, 81703, 154153, 210853, 295873, 327823, 479023, 537583, 568903, 632323, 1111723, 1195543, 1415833, 1626433, 1853443, 2060503, 2146813, 2702893} == 13 mod 30. (End)

Examples

			13 is there because it is prime and 4*13 = 23+29.
		

Crossrefs

Cf. A001043 (sums of two consecutive primes).

Programs

  • Mathematica
    pr = Prime[Range[1000]]; Select[(Total /@ Partition[pr, 2, 1])/4, PrimeQ] (* Zak Seidov, Jun 29 2017 *)
  • PARI
    is(n)=isprime(n) && precprime(2*n)+nextprime(2*n)==4*n \\ Charles R Greathouse IV, Apr 24 2015

Extensions

Edited by Don Reble, Jul 23 2006