21851

Properties

Appears in sequences

• Number of factorization patterns of polynomials of degree n over F_5.at n=21A006170
• Primes followed by an [8,4,8]=[d,D-d,d] prime difference pattern of A001223.at n=10A052377
• Prime number spiral (clockwise, Northeast spoke).at n=25A054553
• Numbers k such that 41^k - 40^k is prime.at n=8A062607
• Balanced primes of order seven.at n=21A096699
• a(0) = 1, a(1) = 1, a(n) = 6*a(n-1) + 5*a(n-2) for n > 1.at n=6A123362
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (-1, 1, -1), (0, 1, 0), (1, -1, 0)}.at n=11A148127
• The smallest prime number greater than 2^n / 3.at n=15A179283
• Primes p with same last two digits as k, where prime(k) = p.at n=25A232102
• A set of nine consecutive primes forming a 3 X 3 semimagic square with the smallest magic constant (65573).at n=3A265614
• Numbers k such that (2*10^k - 179)/3 is prime.at n=17A295394
• Number of non-equivalent ways (mod D_2) to select 4 points from n equidistant points on a straight line so that no selected point is equally distant from two other selected points.at n=31A300761
• Discriminants of imaginary quadratic fields with class number 39 (negated).at n=29A351677
• Primes p such that p + 8, p + 12 and p + 20 are also primes.at n=28A384299
• Prime numbersat n=2451