A096450 Primes p such that the number of primes q, 7 <= q < p, congruent to 1 or 2 mod 5, is equal to the number of such primes congruent to 3 or 4 mod 5.

7, 29, 37, 61, 89, 101, 107, 113, 131, 151, 181, 239, 251, 271, 397, 421, 443, 463, 479, 491, 503, 557, 569, 577, 601, 743, 757, 787, 857, 863, 881, 887, 1291, 1511, 1531, 1549, 1609, 1657, 1667, 1693, 1699, 1861, 1987, 1997, 2003, 2017, 2053, 2377, 2393

Offset

1,1

Comments

First term prime(4) = 7 is placed on 0th row.

If prime(n-1) = 1 or 2 mod 5 is on k-th row then we put prime(n) on (k-1)-st row.

If prime(n-1) = -1 or -2 mod 5 is on k-th row then we put prime(n) on (k+1)-st row.

This process produces the following array of prime numbers:

31, 97, ... row -1

7, 29, 37, 61, 89, 101, ... row 0 (this sequence)

11, 17, 23, 41, 47, 59, 67, 83, ... row 1 (A096454)

13, 19, 43, 53, 71, 79, ... row 2 (A096455)

73, ...

Links

Table of n, a(n) for n=1..49.

Crossrefs

Cf. A096448-A096455.

Sequence in context: A262285 A041088 A107923 * A156124 A155476 A166970

Adjacent sequences: A096447 A096448 A096449 * A096451 A096452 A096453

Keyword

nonn,easy

Author

Yasutoshi Kohmoto, Aug 12 2004

Extensions

More terms and better definition from Joshua Zucker, May 21 2006

Status

approved