23393

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 17.at n=11A031605
• a(n) = prime(n)*prime(n+2).at n=34A090076
• Number of permutations of length n which avoid the patterns 2341, 3214, 4213; or avoid the patterns 1324, 2341, 3214.at n=9A116760
• Numbers n such that the n-th tribonacci number as defined by A000213 is prime.at n=20A157611
• a(n) = prime(n) times the n-th nonnegative noncomposite.at n=36A176098
• Numbers k such that exactly three d in the range d <= k/2 exist which divide binomial(k-d-1,d-1) and which are not coprime to k.at n=20A178099
• S_5 sequence in partition of integers > 1 described in A240521.at n=41A240522
• Number of partitions of n with difference -6 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=44A242686
• Number of (n+2) X (4+2) 0..1 arrays with no 3 x 3 subblock diagonal sum less than the antidiagonal sum or central row sum less than the central column sum.at n=7A258890
• Semiprimes whose prime factors are of equal binary length and which differ from each other in one bit position only.at n=24A261073
• Semiprimes whose prime factors differ from each other in one bit position only.at n=55A261077
• Sequence of pairwise relatively prime numbers of class P_5 (see comment in A275246).at n=17A275249
• Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 382", based on the 5-celled von Neumann neighborhood.at n=29A287950
• Rectangular array R read by antidiagonals: R(n,k) = F(n+1)^k - k*F(n-1)*F(n)^(k-1), where F(n) = A000045(n), the n-th Fibonacci number; n >= 0, k >= 1.at n=50A318405
• Composite hypotenuses of primitive Pythagorean triangles (A120961) that are not circumdiameters of non-Pythagorean primitive Heronian triangles (A285579).at n=34A329148
• Numbers k for which A276085(k) is a multiple of 3125, where A276085 is fully additive with a(p) = p#/p.at n=8A377878
• Stellated octagon numbers: a(n) = 20*n^2 + 8*n + 1.at n=34A381196