20150

Appears in sequences

• a(n) = n*(n+1)*(n+2)*(n+7)/24.at n=24A005582
• a(n) = a(n-1) + a(n-2) + 1, with a(0) = 0 and a(1) = 11.at n=17A022316
• Numbers k such that the sum of the squares of the divisors of k is divisible by k.at n=29A046762
• Numbers k such that k and k+1 have the same sum of non-unitary divisors (A048146), for A048146(k) > 0.at n=5A064115
• Row sums in A083167.at n=25A083170
• a(n) = 4394*n - 1820.at n=4A156627
• a(n) = n*(n + 1)*(7*n + 11)/6.at n=25A255687
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 30", based on the 5-celled von Neumann neighborhood.at n=39A269755
• Two-column table read by rows: Primitive distinct pairs that have the same value of phi, sigma, and tau.at n=29A322688
• Number of regions in a polygon whose boundary consists of n+2 equally spaced points around a semicircle and three equally spaced points along the diameter (a total of n+3 points). See Comments for precise definition.at n=24A333642
• Numbers k such that k and k+1 have the same positive sum of noninfinitary divisors (A348271).at n=0A348346
• a(n) is the smallest k such that the sum of the number of divisors of the n numbers from k to k+n-1 equals tau(k+n).at n=9A348837