3,1

Let p(n) be the sequence of primes, i.e. p(1)=2. For n>=3 we define a(n) = max { m IN N | EXIST c(k), d(k) IN N, k=3, .., n : FOR ALL i IN {1, .., m} EXISTS j IN {3, .., n} : i == c(j) (mod p(j)) OR i == d(j) (mod p(j)) }

a(5) = 10 because c(3)=2, d(3)=4, c(4)=1, d(4)=3, c(5)=4, d(5)=6 satisfy the requirements: 1 == 1 (mod 7), 2 == 2 (mod 5), 3 == 3 (mod 7), 4 == 4 (mod 5), 5 == 5 (mod 11), 6 == 6 (mod 11), 7 == 2 (mod 5), 8 == 1 (mod 7), 9 == 4 (mod 5), 10 == 3 (mod 7)

Cf. A072752.

Sequence in context: A124480 A130967 A065832 this_sequence A009884 A032023 A094837

Adjacent sequences: A072750 A072751 A072752 this_sequence A072754 A072755 A072756

hard,more,nonn

Mario Ziller (datalab(AT)gmx.de), Jul 10 2002

One more term from Mario Ziller (datalab(AT)gmx.de), May 30 2005