140760

Appears in sequences

• Smallest positive number of "triangular" shuffles of n(n+1)/2 cards needed to restore them to their original order.at n=22A048782
• Numbers k such that k-1, k+1, k^2+1 and k^4+1 are all prime numbers.at n=13A070156
• Numbers k such that (k-1, k+1) and (k/2-1, k/2+1) are both pairs of twin primes.at n=19A076504
• Sums of adjacent amicable numbers, a(n) = A063990(2n-1) + A063990(2n).at n=10A161005
• a(n) is the least x such that x-1 and x+1 are prime and there are exactly n primes of the form x-1+t or x+1+t where t divides x.at n=31A340170
• Numbers whose sum of prime divisors equals the sum of square divisors.at n=36A390397