18653

Appears in sequences

• Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 18.at n=54A050967
• a(n) = 1 + 2 * least i such that A103507(i)=n+1, 0 if no such i exists.at n=24A103508
• Number of ways prime(n) can be expressed as the sum of distinct smaller noncomposites.at n=48A215966
• Number of partitions p of n such that 2*(number of even numbers in p) < (number of odd numbers in p).at n=46A241651
• Numbers n such that prime(n) and phi(n) have the same decimal digits.at n=38A243462
• Number of n X 4 binary arrays with rows and columns lexicographically nondecreasing and row and column sums nonincreasing.at n=33A266543
• Number of n X 2 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,1) and new values introduced in order 0..2.at n=12A275395
• Number of permutations of [n] avoiding {1243, 2431, 3412}.at n=10A294695
• Let m(k) be the index of the largest triangular number <= k; then a(n) is the smallest number k that can be written as the sum of three triangular numbers if the largest is the (m(k)-n)-th triangular number, but no larger.at n=13A331753
• Squarefree semiprimes k such that k+1 is the product of three distinct primes and k+2 is the product of four distinct primes.at n=19A376352
• Consecutive states of the linear congruential pseudo-random number generator (419*s + 6173) mod 29282 when started at s=1.at n=20A385036