The OEIS is supported by the many generous donors to the OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A271323 Numbers n such that  n - 41, n - 1, n + 1, n + 41 are consecutive primes. 1
 383220, 1269642, 1528938, 2590770, 3014700, 3158298, 3697362, 3946338, 4017312, 4045050, 4545642, 4711740, 4851618, 4871568, 5141178, 5194602, 5925042, 5972958, 5990820, 6075030, 6179862, 6212202, 6350760, 6442938, 6549312, 6910638, 6912132 (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 - 40 and n + 1 belong to A126721 (p such that p + 40 is the next prime) and A271981 (p and p + 40 are primes). The numbers n - 40 and n ­- 1 belong to A271982 (p and p + 42 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 383220 is the average of the four consecutive primes 383179, 383219, 383221, 383261. 1269642 is the average of the four consecutive primes 1269601, 1269641, 1269643, 1269683. MATHEMATICA Mean/@Select[Partition[Prime[Range], 4, 1], Differences[#] == {40, 2, 40}&] (* Harvey P. Dale, Oct 16 2021 *) PROG (Python) from sympy import isprime, prevprime, nextprime for i in range(0, 12000001, 6): ..if isprime(i-1) and isprime(i+1) and prevprime(i-1) == i-41 and nextprime(i+1) == i+41: print (i, end=', ') CROSSREFS Cf. A014574, A077800 (twin primes), A249674, A256753. Sequence in context: A295454 A273772 A206365 * A205759 A205589 A157843 Adjacent sequences:  A271320 A271321 A271322 * A271324 A271325 A271326 KEYWORD nonn AUTHOR Karl V. Keller, Jr., May 15 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 14 13:43 EDT 2022. Contains 356117 sequences. (Running on oeis4.)