A096450 - OEIS

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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

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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)