31201

Appears in sequences

• Strong pseudoprimes to base 35.at n=12A020261
• Strong pseudoprimes to base 39.at n=18A020265
• Numbers k such that 83*2^k+1 is prime.at n=15A032391
• Smallest integer > 1 which is both n-gonal and centered n-gonal.at n=37A072277
• Molien series for complete weight enumerators of self-dual codes over Z/8Z.at n=16A092544
• Table T(n,k) = -2*T(n-1,k)+T(n-1,k+1) = T(n,k-4), 0<=n.at n=40A140287
• First quadrisection of A140287.at n=10A140289
• a(n) = 78*n^2 + 1.at n=20A158769
• a(n) = n*(n^2 - 4*n + 5)/2.at n=41A162607
• Centered 40-gonal numbers.at n=39A195317
• Number of (w,x,y,z) with all terms in {1,...,n} and 2w*x<=3*y*z.at n=15A211921
• Number of (w,x,y,z) with all terms in {0,...,n} and at least one of them is the range of {w,x,y,z}.at n=16A212746
• 40-gonal numbers: a(n) = 38*n*(n-1)/2 + n.at n=41A261191
• Number of subsets of {1,..,n} of cardinality >= 2 such that the elements of each counted subset are pairwise coprime.at n=29A276187
• Number of compositions (ordered partitions) of n into odd divisors of n.at n=49A284466
• Semiprimes k = pq such that p^k == p (mod k) and q^k == q (mod k).at n=28A294169
• Number of compositions of n^2 into powers of n.at n=7A333048
• E.g.f. A(x) satisfies A(x) = 1/( 1 - sin(x * A(x)^2) ).at n=5A381388