This site is supported by donations to The OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A273356 Numbers n such that n - 49, n - 1, n + 1, n + 49 are consecutive primes. 1
 913638, 2763882, 4500492, 6220518, 6473148, 13884468, 15131982, 15729942, 19671930, 20494602, 21372888, 23791350, 25541028, 29535348, 30787788, 30906768, 32085372, 34128168, 34139802, 34550430, 35989980, 37473180, 37784310, 38106372 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is a subsequence of A014574 (average of twin prime pairs) and A256753. The terms ending in 0 belong to A249674 (divisible by 30). The terms ending in 2 (resp. 8) are congruent to 12 (resp. 18) mod 30. The numbers n - 49 and n + 1 belong to A134123 (p such that p + 48 is the next prime). The numbers n - 49 and n -­ 1 belong to A062284 (p and p + 50 are primes). LINKS Karl V. Keller, Jr., Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Twin Primes EXAMPLE 913638 is the average of the four consecutive primes 913589, 913637, 913639, 913687. 2763882 is the average of the four consecutive primes 2763833, 2763881, 2763883, 2763931. PROG (Python) from sympy import isprime, prevprime, nextprime for i in range(0, 60000001, 6): ..if isprime(i-1) and isprime(i+1) and prevprime(i-1) == i-49 and nextprime(i+1) == i+49: print (i, end=', ') (PARI) is(n)=isprime(n-1) && isprime(n+1) && precprime(n-2)==n-49 && nextprime(n+2)==n+49 \\ Charles R Greathouse IV, Jun 08 2016 CROSSREFS Cf. A014574, A077800 (twin primes), A249674, A256753. Sequence in context: A236617 A237155 A112688 * A253991 A253998 A258908 Adjacent sequences:  A273353 A273354 A273355 * A273357 A273358 A273359 KEYWORD nonn AUTHOR Karl V. Keller, Jr., May 20 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 26 00:20 EDT 2019. Contains 321478 sequences. (Running on oeis4.)