19453

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 76 ones.at n=31A031844
• Denominators of continued fraction convergents to sqrt(140).at n=8A041257
• a(n) = T(4,n), array T given by A047858.at n=11A047861
• In base 4, n sets a new record for the number of Reverse and Add! steps needed to reach a palindrome starting with n.at n=12A075686
• a(n) = K_3(n) = Sum_{k>=0} A090285(3,k)*2^k*binomial(n,k). a(n) = (4*n^3+30*n^2+56*n+15)/3.at n=22A090294
• Triangle T(n, d) = the number of isomorphism classes of smooth Fano d-polytopes with n vertices, read by rows (n >= 2, 1 <= d < n).at n=62A127709
• Integers n such that by inserting between their digits + or - or * or / or ^ or nothing (i.e., concatenate two digits) you recover n back in a nontrivial way.at n=18A157198
• Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=3, k=-1 and l=1.at n=8A176964
• Number of (w,x,y,z) with all terms in {1,...,n} and w+x+y=|x-y|+|y-z|.at n=42A212678
• Sums of Pythagorean sextuples in increasing order: The sums of sets of six natural numbers which correspond to the lengths of the edges of a tetrahedron whose four faces are all different Pythagorean triangles.at n=34A248548
• First occurrence of a run of exactly n consecutive integers with an odd number of prime factors.at n=12A275509
• p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = 1 - S - S^3.at n=16A291735
• a(n) = n*2^10 - 3.at n=18A362361