143256

Appears in sequences

• Numbers with 6 distinct digits {1,2,3,4,5,6} such that all adjacent digits (as well as first and last digits) are coprime.at n=1A104973
• a(n) is the concatenation of the numbers appearing in row n of the lexicographically earliest prime pyramid (A051237).at n=5A187869
• a(1)=1; for n > 1, a(n) is the smallest number that is formed by arranging the decimal numbers "1", "2", ..., "n" in some order so that the sum of every pair of adjacent numbers "i" "j" is prime.at n=5A187871
• Numbers m such that m | A000385(m-1) = Sum_{k=1..m-1} sigma(k) * sigma(m-k).at n=36A326608