18445

Appears in sequences

• Hexagonal pyramidal numbers, or greengrocer's numbers.at n=30A002412
• Expansion of Product_{k>=1} (1-x^k)^31.at n=4A010836
• Odd hexagonal pyramidal numbers.at n=15A015225
• Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,2,1.at n=5A037563
• a(n) = Sum_{i=1..n} Sum_{j=1..i} (prime(i) - prime(j)).at n=29A062020
• Numbers n such that the middle coefficient of the cyclotomic polynomial Phi_n(x) has a value not obtained for any smaller n.at n=12A095877
• Smallest order of the cyclotomic polynomial whose maximal coefficient in absolute value is n.at n=18A136418
• Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 10000-11111-10000 pattern in any orientation.at n=16A147081
• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1101-0111 pattern in any orientation.at n=16A147166
• Number of binary strings of length n with no substrings equal to 0000 0101 or 1010.at n=13A164434
• Number triangle with row sums given by quadruple factorial numbers A001813.at n=32A168422
• Numbers k such that 3k-4, 3k-2, 3k+2, and 3k+4 are primes.at n=26A173092
• Binomial transform of A113127; (1, 1, 3, 7, 15, 31, ...) convolved with (1, 3, 7, 15, 31, 63, ...).at n=10A181527
• Degrees of irreducible representations of orthogonal group O10+(2).at n=15A214472
• Degrees of irreducible representations of orthogonal group O10+(2).at n=16A214472
• The least k such that the polynomial cyclotomic(k,x) has n different coefficients.at n=38A231611
• Number of (n+1)X(1+1) 0..3 arrays x(i,j) with row sums sum{x(i,j), j=1..1+1} nondecreasing, and column sums sum{i^2*x(i,j), i=1..n+1} nondecreasing.at n=3A233351
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays x(i,j) with row sums sum{x(i,j), j=1..k+1} nondecreasing, and column sums sum{i^2*x(i,j), i=1..n+1} nondecreasing.at n=9A233353
• Numbers n such that n^6+6 and n^6-6 are prime.at n=2A239429
• Numbers n such that 19^n+4 is prime.at n=9A243397