A288639 Products of two distinct numbers that are the average of a pair of twin primes.

24, 48, 72, 108, 120, 168, 180, 216, 240, 252, 288, 360, 408, 432, 504, 540, 552, 600, 612, 648, 720, 756, 768, 792, 828, 864, 900, 912, 960, 1080, 1128, 1152, 1188, 1224, 1248, 1260, 1296, 1368, 1392, 1440, 1620, 1656, 1680, 1692, 1728, 1800, 1836, 1848

Offset

1,1

Links

Table of n, a(n) for n=1..48.

Example

4 and 12 are two distinct numbers that are averages of twin prime pairs (i.e., 4 = (3+5)/2 and 12 = (11+13)/2), and 4*12 = 48, which is in the sequence.

Mathematica

m = 1 + Select[Range@1000, PrimeQ[#] && PrimeQ[# + 2] &]; Select[v Union@ Flatten@ Table[m[[i]] m[[j]], {i, Length[m]}, {j, i - 1}], # <= 4000 &] (* Giovanni Resta, Jun 13 2017 *)

Crossrefs

Cf. A014574, A249628.

Subset of A286195.

Sequence in context: A317971 A141767 A327947 * A280097 A054734 A174906

Adjacent sequences: A288636 A288637 A288638 * A288640 A288641 A288642

Keyword

nonn

Author

Wesley Ivan Hurt, Jun 12 2017

Extensions

More terms from Giovanni Resta, Jun 13 2017

Status

approved