A210957 Prime pair (p, q), p<=q, such that p + q = 2*n and p*q is the minimal product.

2, 2, 3, 3, 3, 5, 3, 7, 5, 7, 3, 11, 3, 13, 5, 13, 3, 17, 3, 19, 5, 19, 3, 23, 5, 23, 7, 23, 3, 29, 3, 31, 5, 31, 7, 31, 3, 37, 5, 37, 3, 41, 3, 43, 5, 43, 3, 47, 5, 47, 7, 47, 3, 53, 5, 53, 7, 53, 3, 59, 3, 61, 5, 61, 7, 61, 3, 67, 5, 67, 3, 71, 3, 73

Offset

2,1

Comments

A020481 and A020482 interleaved.

Links

Table of n, a(n) for n=2..75.

Formula

p_n = A020481(n), n >= 2.

q_n = A020482(n), n >= 2.

p_n + q_n = 2*n, n >= 2.

p_n * q_n = A073046(n), n >= 2.

Example

-----------------------------------
                 2*n    A073046(n)
       Pair       =         =
n     (p, q)     p+q       p*q
-----------------------------------
2     (2, 2)      4          4
3     (3, 3)      6          9
4     (3, 5)      8         15
5     (3, 7)     10         21
6     (5, 7)     12         35
7     (3, 11)    14         33
8     (3, 13)    16         39
9     (5, 13)    18         65
10    (3, 17)    20         51
11    (3, 19)    22         57
12    (5, 19)    24         95

Crossrefs

Cf. A000040, A002373, A073046, A210967.

Sequence in context: A136132 A136545 A125843 * A306246 A147665 A222820

Adjacent sequences: A210954 A210955 A210956 * A210958 A210959 A210960

Keyword

nonn

Author

Omar E. Pol, Jun 29 2012

Status

approved