158748domain: NAppears in sequencesNumber of -n..n arrays x(0..3) of 4 elements with zero sum and nonzero first and second differences.at n=30A200456Averages k of twin prime pairs such that A075255(k) is also the average of a twin prime pair.at n=23A340570Expansion of 1 / ((1-x)^2 - x^6)^2.at n=23A392554