17981
domain: N
Properties
Primality
- Prime
- yes
Appears in sequences
- Expansion of 1/((1-x^2)*(1-x^4)^2*(1-x^6)*(1-x^8)*(1-x^10)) (even powers only).at n=47A001994
- 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 53.at n=0A031641
- Primes of the form 666*k - 1.at n=9A063472
- 24 'Reverse and Add' steps are needed to reach a palindrome.at n=3A065318
- Number of partitions of n in which the sequence of frequencies of the summands is nondecreasing.at n=41A100883
- Numbers k such that the k-th triangular number contains only digits {1,6,7}.at n=15A119141
- Number of base 5 n-digit numbers with adjacent digits differing by two or less.at n=7A126392
- Primes congruent to 14 mod 53.at n=38A142544
- Primes congruent to 45 mod 59.at n=37A142772
- Primes congruent to 47 mod 61.at n=34A142845
- 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, 1, -1), (0, 1, -1), (1, 0, 1)}.at n=10A148583
- 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, 1), (-1, 1, -1), (-1, 1, 1), (1, -1, 0), (1, 1, 1)}.at n=8A149574
- 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), (0, 0, -1), (1, -1, 0), (1, 1, 1)}.at n=8A149665
- Primes p such that 12*p^3+-1 are twin primes.at n=13A158297
- n-th prime is a circular prime (A016114).at n=18A173819
- T(n,k)=Number of -k..k arrays of n elements with adjacent element differences also in -k..k.at n=34A201042
- Number of -n..n arrays of 7 elements with adjacent element differences also in -n..n.at n=1A201046
- Denominators of upper primes-only best approximates (POBAs) to Pi; see Comments.at n=17A265811
- Array read by antidiagonals: T(m,n) = number of m-ary words of length n with adjacent elements differing by 2 or less.at n=47A285266
- Number of 6-cycles in the n-triangular honeycomb obtuse knight graph.at n=14A290392