30637

Properties

Appears in sequences

• a(n) = n*a(n-1) + (n-3)*a(n-2), with a(1) = 0, a(2) = 1.at n=7A000261
• 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 18.at n=14A031606
• Number of partitions of n into parts not of the form 17k, 17k+5 or 17k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 7 are greater than 1.at n=42A035966
• Primes of the form 666*n + 1.at n=15A037029
• Primes p from A031924 such that A052180(primepi(p)) = 13.at n=37A052233
• Second term of balanced prime quartets: p(m)-p(m-1) = p(m+1)-p(m) = p(m+2)-p(m+1).at n=18A054801
• Triangular array formed from successive differences of factorial numbers, then with factorials removed.at n=51A060475
• Sums of groups in A075635.at n=36A075636
• Table T(n,k) giving number of ways of obtaining exactly 0 correct answers on an (n,k)-matching problem (1 <= k <= n).at n=41A076731
• Triangle T(n, k), read by row, related to Euler's difference table A068106 (divide column k of A068106 by k!).at n=48A086764
• Numbers which are primes and which remain prime for three successive applications of incrementing each digit by 2 with carries ignored.at n=29A088787
• a(n) = (1/n!)*A023043(n).at n=3A094795
• Smallest prime ending in prime(n) and == 1 (mod prime(n)), or 0 if no such prime exists.at n=11A096069
• Primes of the form k^2 + 12.at n=26A138368
• Numbers k such that k and k+6 are both balanced primes.at n=18A173892
• Tenth prime p such that (p+n)^2+n is prime but (p+j)^2+j is not prime for all 0<j<n.at n=16A238682
• Square array read by antidiagonals: A(k, n) = (-1)^(n+1)* hypergeom([k, -n+1], [], 1) for n>0 and A(k,0) = 0 (n>=0, k>=1).at n=62A247490
• T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with no element 1 greater than its north or northeast neighbor modulo n and the upper left element equal to 0.at n=24A266599
• Number of 4Xn arrays containing n copies of 0..4-1 with no element 1 greater than its north or northeast neighbor modulo 4 and the upper left element equal to 0.at n=3A266601
• T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with no element 1 greater than its west or southwest neighbor modulo n and the upper left element equal to 0.at n=24A267072