A075552 -id:A075552 - cp's OEIS frontend

A074311 a(1) = 1; a(2) = 2; a(n) = smallest number greater than the previous term such that the average of three successive terms is a prime.

1, 2, 3, 4, 8, 9, 16, 26, 27, 34, 50, 57, 70, 74, 75, 88, 104, 111, 112, 116, 153, 178, 188, 207, 238, 242, 243, 268, 278, 285, 286, 308, 327, 358, 362, 381, 394, 416, 417, 424, 452, 453, 466, 470, 501, 502, 506, 519, 538, 566, 567, 574, 590, 597, 610, 614, 615

Offset: 1

Zak Seidov, Sep 23 2002

nonn

Inspired by A073627, A073628. Primes generated in the sequence are in A075551. Primes generated in A073628 are in A075552.

			a(5) = 8 because 1/3(a(3) + a(4) + a(5)) is a prime.

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Cf. A073627, A073628, A075551, A075552.

sngpt[{a_,b_}]:=Module[{k=b+1},While[CompositeQ[Mean[{a,b,k}]],k++];{b,k}]; NestList[sngpt,{1,2},60][[All,1]] (* Harvey P. Dale, May 29 2019 *)

A075551 Primes generated in A074311.

Original entry on oeis.org

2, 3, 5, 7, 11, 17, 23, 29, 37, 47, 59, 67, 73, 79, 89, 101, 109, 113, 127, 149, 173, 191, 211, 229, 241, 251, 263, 277, 283, 293, 307, 331, 349, 367, 379, 397, 409, 419, 431, 443, 457, 463, 479, 491, 503, 509, 521, 541, 557, 569, 577, 587, 599, 607, 613, 617

Offset: 1

Zak Seidov, Sep 23 2002

nonn

Inspired by A073627, A073628. Primes generated in the sequence are in A075551. Primes generated in A073628 are in A075552.

Cf. A073627, A073628, A074311, A075552.

cp's OEIS Frontend

A074311 a(1) = 1; a(2) = 2; a(n) = smallest number greater than the previous term such that the average of three successive terms is a prime.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs