login
A351649
a(n) = minimal average of a pair of twin primes m, such that m * twin_prime(n) is the average of another pair of twin primes, or -1 if no m exists.
0
4, 6, 6, 18, 150, 6, 12, 12, 42, 30, 30, 18, 462, 18, 570, 42, 6, 6, 102, 6, 12, 12, 420, 192, 18, 600, 5100, 570, 18, 4050, 30, 42, 18, 60, 12, 12, 6, 102, 6, 6, 108, 42, 42, 18, 570, 30, 180, 108, 2970, 12, 60, 270, 12, 60, 42, 60, 1950, 102, 108, 18, 72, 348
OFFSET
1,1
LINKS
Carlos Rivera, Puzzle 1075: A conjecture about twin primes, The Prime Puzzles and Problems Connection.
EXAMPLE
11 is the fourth twin prime, i.e., A001097(4). 18 is the minimal average of a twin prime pair, i.e., (17,19), where 18*11=198 is the average of the twin prime pair (197,199). So, a(4)=18.
CROSSREFS
Sequence in context: A346675 A077038 A053320 * A019090 A145692 A295512
KEYWORD
nonn
AUTHOR
Ivan N. Ianakiev, Feb 16 2022
EXTENSIONS
More terms from Jinyuan Wang, Feb 16 2022
STATUS
approved