18581

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 10.at n=27A031423
• Palindromic Super-2 Numbers.at n=34A032750
• Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 15.at n=23A051980
• a(1) = 8; a(n) = smallest palindromic number of the form k*a(n-1) + 1 with k > 1.at n=4A069509
• Rounded total surface area of a regular dodecahedron with edge length n.at n=30A071397
• G.f.: 1/(1-G001190), where G001190 = x + x^2 + x^3 + 2x^4 + 3x^5 + ... is the g.f. for the Wedderburn-Etherington numbers A001190.at n=13A085748
• Palindromes in A085932.at n=8A085933
• Palindromic hypotenuses in primitive Pythagorean triples.at n=31A087456
• Modified Schroeder numbers for q=3.at n=45A114292
• Modified Schroeder numbers for q=3.at n=46A114292
• First row of Modified Schroeder numbers for q=3 (A114292).at n=9A114296
• Numerator of Euler(n,1/3).at n=7A156179
• Palindromic Ulam numbers.at n=33A173542
• 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)=8, k=1 and l=1.at n=6A177124
• Palindromes greater than 10 whose sum of proper divisors is also a palindrome greater than 10.at n=8A227228
• Each term is a palindrome such that the sum of its proper divisors is a palindrome > 1.at n=12A227947
• Numbers m such that m^2 divides 2^k - 1 for some k, 0 < k <= m.at n=11A246503
• Indices of powers of two in A055744 (the sequence of n that have the same prime power set as phi(n)).at n=29A256248
• Palindromes with no palindromic aliquot parts except 1.at n=22A257973
• Number of integer partitions of the n-th semiprime into semiprimes.at n=40A338902