40138

Appears in sequences

• Least k such that k*Mersenne - prime(n) + 1 is prime.at n=23A098556
• Nearest k to j such that k*(2^j-1)+1 is prime where j=A000043(n) and 2^j-1 = Mersenne-prime(n) = A000668(n). If there are two k values equidistant from j, each of which produces a prime, the larger of the two gets added to the sequence.at n=23A159585
• Numbers that are the sum of seven fifth powers in two or more ways.at n=33A345605
• Numbers that are the sum of seven fifth powers in exactly two ways.at n=33A346279