19982

Appears in sequences

• Number of partitions of n with equal nonzero number of parts congruent to each of 2 and 3 (mod 5).at n=49A035569
• Consider trajectory of n under repeated applications of the function f(x) = 'Sum of the prime factors of x (with multiplicity)' (see A029908). Sequence gives composite numbers n that end at a prime m that divides n and m is greater than any m's seen already.at n=9A084931
• Least number that requires exactly n iterations of f(x) = reverse(x) - maxdigit(x) to reach zero.at n=26A097156
• Numbers that set a new record for the number of iterations needed to reach 0 under f(x) = reverse(x) - maxdigit(x).at n=22A097158
• Smallest m such that A098371(m) = n.at n=49A098373
• Sum of primes between n and n^2.at n=21A109818
• Numbers n such that primorial(n)/2 - 1024 is prime.at n=18A139456
• Number of 4-step S, NW and NE-moving king's tours on an n X n board summed over all starting positions.at n=28A187378
• Symmetric triangle T, read by rows, where the matrix product of T and T transpose yields a square array which, when read by antidiagonals, equals this triangle read by rows.at n=56A194949
• Symmetric triangle T, read by rows, where the matrix product of T and T transpose yields a square array which, when read by antidiagonals, equals this triangle read by rows.at n=64A194949
• Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two or four distinct values for every i,j,k<=n.at n=11A211567
• Number of partitions of (3, n) into a sum of distinct pairs.at n=29A268346
• Squarefree numbers k such that the sum of the distinct prime factors of k is twice the difference between the largest and the smallest prime factors of k.at n=21A324210
• Number of tripling steps to reach 1 in the 3x+1 (Collatz) problem starting with the n-th Mersenne prime.at n=18A390817