31972

Appears in sequences

• a(1) = 1, a(2) = 2; for n >= 2, a(n+1) = a(n) + sum of the unique prime factors of a(n).at n=39A096460
• Number of 7-step self-avoiding walks on an n X n square summed over all starting positions.at n=8A188152
• Expansion of 1/(1 + x + x/(1 + x^2 + x^2/(1 + x^3 + x^3/(1 + x^4 + x^4/(1 + ...))))), a continued fraction.at n=42A292854
• Numerator of the barycenter of first n primes defined as a(n) = numerator(Sum_{i=1..n} (i*prime(i)) / Sum_{i=1..n} prime(i)).at n=44A306834
• a(n) is the sum of the terms of the symmetric square array defined by M(i,j) = prime(i)+i-j for i >= j and M(i,j) = M(j,i) if i < j.at n=22A308731
• Sum of the prime numbers in, but not on the border of, an n X n square array whose elements are the numbers from 1..n^2, listed in increasing order by rows.at n=25A344847