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A134969
List of pairs of primes that are separated by the equivalent of 2 quadratic intervals. Both primes are greater than their preceding perfect squares by the same amount, or offset. The respective perfect squares can be both odd, in which case the offset is even, or both even, in which case the offset is odd.
0
3, 11, 5, 17, 7, 19, 13, 29, 17, 37, 23, 43, 29, 53, 43, 71, 67, 103, 71, 107, 73, 109, 97, 137
OFFSET
1,1
LINKS
Michael M. Ross, Diagram of paired primes showing how two perfect pairs partially overlap: 23 and 43 span perfect squares 25 and 36; 29 and 53 span perfect squares 36 and 49.
Michael M. Ross, VBA source code providing an Excel visualization of the odd-offset prime pairs and colocation with twin primes.
FORMULA
PS1 + OfN = P1, PS3 + OfN = P2, where
PS1 = first perfect square,
PS3 = 3rd perfect square,
OfN = an equal positive offset from preceding perfect square, and
P1 and P2 = the prime pair.
EXAMPLE
Prime pair 71 and 107 have an odd offset of 7 from 64 and 100:
Interval 1: 8*8 = 64 + 7 = 71.
Interval 2: 9*9 = 81 + 7 = 88.
Interval 3: 10*10 = 100 + 7 = 107.
Prime pair 97 and 137 have an even offset of 16 from 81 and 121:
Interval 1: 9*9 = 81 + 16 = 97.
Interval 2: 10*10 = 100 + 16 = 116.
Interval 3: 11*11 = 121 + 16 = 137.
In all cases there is a complete intermediate quadratic interval (#2).
The pair (11,83), 11-9 = 83-81 = 2, does not work because there are 6 squares in between: 16,25,36,49,64,81.
PROG
Excel VBA available at http://www.naturalnumbers.org/quadprimes.html#code Demonstrates odd-offset prime-pair distribution with associated twin primes. Limitations: -Only the subset of paired primes for even perfect squares with odd offsets are demonstrated. -Because of the 256-column limitation for an Excel worksheet, data in rows after perfect square 484 are not complete. -Only twin primes that are also paired primes are outlined (in red).
CROSSREFS
Cf. A056892.
Sequence in context: A084466 A084462 A156320 * A139686 A212782 A130537
KEYWORD
nonn,tabf,more,less
AUTHOR
Michael M. Ross, Feb 04 2008
STATUS
approved