20149

Properties

Appears in sequences

• Coordination sequence for MgNi2, Position Mg2.at n=35A009935
• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite RUT = RUB-10 R4[B4Si32O72] starting from a T1 atom.at n=13A019234
• Numbers k such that the continued fraction for sqrt(k) has period 87.at n=12A020426
• Primes that remain prime through 4 iterations of function f(x) = 6x + 5.at n=22A023317
• Euclid-Mullin sequence (A000945) with initial value a(1)=127 instead of a(1)=2.at n=17A051335
• Primes p such that p, p+12, p+24 are consecutive primes.at n=18A052188
• Numbers n such that n, 10*n+1, 10*n+3, 10*n+7 and 10*n+9 are all primes.at n=4A067267
• Trajectory of n under the Reverse and Add! operation carried out in base 3 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.at n=46A077405
• Numbers k such that (5^k - 2^k)/3 is prime.at n=16A082182
• a(1) = 2, a(n+1) = smallest prime of the form a(n) + k*prime(n+1), k >1.at n=35A085041
• Expansion of g.f. Product((1+x^i)/(1-x^i),i=1..n-1)/(1-x^n), with n = 7.at n=28A091778
• a(1) = 3; for n > 1 a(n) is the least prime of form a(n-1) + k*prime(n-1) with k > 0.at n=36A095184
• First prime divisor of odd composite Mersenne prime reversals.at n=6A134039
• Mother primes of order 11.at n=28A136070
• Primes congruent to 19 mod 61.at n=35A142817
• 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, 0), (1, -1, 0), (1, 0, -1), (1, 1, 1)}.at n=8A149680
• Primes in toothpick sequence A153006.at n=25A153009
• Primes of the form 2*n^2 + 22*n + 9.at n=13A154601
• Primes p such that (p-1)*p*(p+1)-p+2 and (p-1)*p*(p+1)+p-2 are primes.at n=29A154944
• Number of reduced words of length n in the Weyl group B_25.at n=4A161932