18490

Appears in sequences

• Ruth-Aaron numbers (2): sum of prime divisors of n = sum of prime divisors of n+1 (both taken with multiplicity).at n=25A039752
• Numbers k such that the k-th difference between 2 successive primes equals the squarefree part of k.at n=31A078691
• Sequence is identical to its third differences in absolute values: a(n+k)=3a(n+k-1)-3a(n+k-2)+2a(n+k-3), k=0, 1, 2, 3, 4, a(n+5)=3a(n+4)-3a(n+3), n > 2.at n=16A132418
• The sum of the principal diagonals of an n X n spiral.at n=30A137930
• Sum of the principal diagonals of a 2n X 2n square spiral.at n=15A137931
• Numbers n, satisfying A055231(n+1) - A055231(n) = 1, and with n and n+1 not squarefree.at n=2A140394
• Half the number of length n integer sequences with sum zero and sum of squares 6272.at n=3A157588
• Smallest integer m > n such that both n*m and (n+1)*(m+1) are squares.at n=10A212651
• Numbers k such that core(k+1) = core(k)+1 and k is not squarefree, where core(k) = A007913(k).at n=5A260198
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 283", based on the 5-celled von Neumann neighborhood.at n=29A271119
• a(n) = n * (4*n + 3)^2.at n=10A322675
• Numbers k such that 459*2^k+1 is prime.at n=41A323199
• Numbers k such that A063659(k) = A063659(k+1).at n=3A336673
• a(n) = A152534(n,n).at n=9A346980
• Numbers k such that k and k+1 are both divisible by the square of their largest prime factor.at n=16A354558