40104

Appears in sequences

• Numerators of continued fraction convergents to sqrt(107).at n=7A041192
• Palindromes that start with 4.at n=23A043039
• Palindromes with exactly 6 prime factors (counted with multiplicity).at n=15A046332
• Indices of triple-safe primes: p=prime(n) is double-safe: q=(p-1)/2, r=(q-1)/2 and s=(r-1)/2 are all prime (and q is double-safe).at n=27A075134
• a(n) = n^2 concatenated with reverse(n^2) divided by 11.at n=21A084009
• Palindromes with digit sum 9.at n=14A121476
• Numbers k with squares that are concatenations k^2 = x//y such that x is an anagram of y.at n=9A162945
• Number of 4-step left-handed knight's tours (moves only out two, left one) on an n X n board summed over all starting positions.at n=36A187174
• Triangle read by rows: T(n,k) is the number of subpermutations of an n-set whose orbits are each of size at most k, and without fixed points. Equivalently, T(n,k) is the number of partial derangements of an n-set each of whose orbits is of size at most k.at n=32A261762
• a(n) = palindrome arising when A228407(n+1) is formed (if there is more than one, use the smallest).at n=20A303571
• a(n) = palindrome arising when A228410(n+1) is formed (if there is more than one, use the smallest).at n=21A303572
• Consider all 3 X 3 matrices M whose entries are the n-th to (n+8)-th primes prime(n), ..., prime(n+8), in any order. a(n) is the sum of the number of M such that det(M) is divisible by prime(n+i), for i from 0 to 8.at n=17A339105