18361

Appears in sequences

• Number of nonnegative solutions to x^2 + y^2 + z^2 <= n^2.at n=32A000604
• Expansion of e.g.f.: 1 + x*exp(x) + x^2*exp(2*x) + x^3*exp(3*x).at n=7A003014
• Pseudoprimes to base 6.at n=37A005937
• Strong pseudoprimes to base 80.at n=16A020306
• Convolution of odd numbers and primes.at n=25A023662
• Numbers k such that 251*2^k+1 is prime.at n=15A032502
• a(n) = (2*n+1)*(10*n+1).at n=30A033574
• Gaps of 9 in sequence A038593 (upper terms).at n=15A038658
• Numbers k such that k divides the numerator of B(2k) (the Bernoulli numbers), but gcd(3k, 8^k+1) > 3.at n=37A070192
• Numbers n such that A001414(n) = sum of squared digits of n.at n=34A094908
• Heptagonal numbers for which the digital root is also a heptagonal number.at n=40A117663
• Heptagonal numbers divisible by 7.at n=25A117795
• Number of nodes (or order) of a graph model obtained using an automata scheme on sets of order prime(n) >= 5 and in which all not halt states are linked by arcs (edges).at n=30A160772
• Number of binary strings of length n with equal numbers of 01010 and 10001 substrings.at n=15A164262
• Triangle T(n,k) read by rows of the smallest n-gonal number greater than 1 that is also k-gonal, or 0 if none exists, for 3 <= k <= n.at n=49A189216
• a(n) = n*(10*n-3).at n=43A195018
• a(n) = Sum_{d|n} d * sigma(n/d, d).at n=19A198302
• Number of (w,x,y) with all terms in {0,...,n} and |w-x| + |x-y| + |y-w| >= w + x + y.at n=39A213489
• Antidiagonal sums of the convolution array A213774.at n=12A213776
• Numbers n such that sum of squares of digits of n equals the sum of prime divisors of n.at n=39A217390