18202

Appears in sequences

• a(n) = [ 1/(2*t(n+1) - t(n) - t(n+2)) ], where t(n) = tan(Pi/2 - 1/n) satisfies n-1 < t(n) < n for all n >= 1.at n=21A024817
• a(n) = Sum_{k=0..n} (k+1) * A026736(n,n-k).at n=11A027220
• "CGK" (necklace, element, unlabeled) transform of 2,2,2,2,...at n=17A032156
• T(n,n-3), array T as in A054110.at n=35A054112
• Integers i > 1 for which there is no prime p such that i is a solution mod p of x^4 = 2.at n=33A065903
• If p(k) is the k-th prime, then the n-th set of 3 consecutive cousin prime pairs starts at p(a(n)).at n=24A095970
• Numerator of Euler(n, 2/21).at n=4A156777
• Number of permutations of 1..n containing the relative rank sequence { 135642 } at any spacing.at n=3A159102
• Number of permutations of 1..n containing the relative rank sequence { 136452 } at any spacing.at n=3A159106
• Number of permutations of 1..n containing the relative rank sequence { 143625 } at any spacing.at n=3A159111
• Numbers n such that the sum of the squares of the digits of n^n is a square.at n=21A171976
• a(n) = 5*2^n/9 + 1/4 + (-1)^n*(n/6 + 7/36).at n=15A172416
• a(n) = (-1 + 5*2^(2*n + 1) - 3*n)/9.at n=7A172447
• G.f.: 1+x = Sum_{n>=0} a(n) * x^n * Product_{k=1..n} (1 - k*x)/(1 + k*x).at n=6A208833
• Triangle of coefficients of polynomials v(n,x) jointly generated with A209168; see the Formula section.at n=49A209169
• a(n) = prime(n)^3 mod (n^2 + prime(n)^2).at n=43A243769
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 630", based on the 5-celled von Neumann neighborhood.at n=33A269543
• Number of triangles of weight prime(n) in the multiorder of integer partitions of prime numbers into prime parts.at n=11A316219
• Number of n-phobe numbers.at n=9A349189
• Number of balanced unate functions of n or fewer variables.at n=5A373690