123609

Appears in sequences

• Odd numbers n divisible by 3 such that for all k >= 1 the numbers n*2^k - 1 and n*2^k + 1 do not form a twin prime pair.at n=17A237592
• Length of n-th iterate of the mapping 00->0010, 01->010, 10->000, starting with 00.at n=19A289019