19018

Appears in sequences

• a(n) = (2*n - 1)*(3*n^2 - 3*n + 2)/2.at n=18A063491
• Let spm(n) be the sum of all prime factors of n counted with multiplicities (A001414); sequence gives numbers n such that spm(n+spm(n)) divides both n and n+spm(n).at n=11A131564
• One fifth of product plus sum of five consecutive nonnegative numbers.at n=8A166942
• a(n) = n^2 + a(n-1), with a(1)=0.at n=37A168559
• Take first n bits of the infinite Fibonacci word A003849, regard them as a binary number, then convert it to base 10.at n=15A182028
• a(n) = 14*n^2 - 4*n.at n=37A195023
• First differences of A182028.at n=15A214319
• a(n) = binary code (shown here in decimal) of the position of natural number n in the beanstalk-tree A218776.at n=38A218615
• a(n) = binary code (shown here in decimal) of the position of the predecessor of the natural number pair (2n,2n+1) in the compact beanstalk-tree A218780.at n=20A218791
• Number of n X 2 -2..2 arrays of 2 X 2 subblock diagonal sums minus antidiagonal sums for some (n+1) X 3 binary array with rows and columns of the latter in lexicographically nondecreasing order.at n=9A227056
• Sequence shifts left five places under Weigh transform with a(n) = signum(n) for n<5.at n=34A316077
• a(n) is the smallest number which can be represented as the sum of n distinct perfect powers (A001597) in exactly n ways, or -1 if no such number exists.at n=44A363040
• a(n) = Sum_{k=0..n} A001595(k)^2.at n=9A375500
• Numbers k such that the total number of digits d in the numbers from 1 to k is even for each d from 0 to 9.at n=40A380642