-494

Appears in sequences

• Reversion of divisor function A000005.at n=5A050389
• Start with 1, add the next number if one gets a prime then add the next number else subtract the next...at n=34A074170
• Expansion of g.f. (1+x)^2/((1 + x + x^2)*(1 + x - x^2)).at n=17A106511
• Expansion of (1 + x)^2/((1 + x + x^2)*(1 + 3*x + x^2)).at n=7A113066
• Coefficients of the invariant of degree 20 associated with the icosahedral group.at n=2A128808
• A coefficient tree from the list partition transform relating A111884, A084358, A000262, A094587, A128229 and A131758.at n=13A131202
• Expansion of (1-2x-5x^2-7x^3+x^6)/((1-x)(1-x^3)^2).at n=26A141352
• Expansion of f(x) * f(x^5) / phi(-x^10)^2 in powers of x where f(), phi() are Ramanujan theta functions.at n=67A147699
• Triangle formed by coefficients of the expansion of p(x, n), where p(x,n) = (1 + 2*x - x^2)^(n + 1)*Sum_{j >= 0} (j+1)^n*(-2*x + x^2)^j.at n=51A156901
• Expansion of (1+4*x+x^2) / ((1-x)^3*(1+x)^4).at n=22A229834
• Expansion of 1/((1-x)^2*(1-2*x+2*x^2)).at n=15A279230
• Expansion of 1 - x/(1 - x^3/(1 - x^6/(1 - x^10/(1 - x^15/(1 - x^21/(1 - ... - x^(n*(n+1)/2)/(1 - ...))))))), a continued fraction.at n=54A290976
• a(n) = Sum_{k=0..floor(n/8)} (-1)^k*binomial(n,8*k).at n=12A307044
• a(n) = 2*1 - 4*3 + 6*5 - 8*7 + 10*9 - 12*11 + 14*13 - 16*15 + ... - (up to the n-th term).at n=32A319885
• a(n) = Sum_{d|n} (-1)^(d-1)*d^2.at n=19A321543
• G.f.: Sum_{n>=0} (x^(2*n-1) + 1)^n * x^n / (1 + x^(2*n+1))^(n+1), an even function.at n=31A326602
• a(n) = n - 2^(sum of digits of n).at n=18A328882
• a(n) = Sum_{d|n} mu(d) * binomial(d + n/d - 2, d-1).at n=44A338656
• Counterclockwise square spiral constructed using the integers so that a(n) plus all other numbers currently visible from the current number equals n; start with a(0) = 0.at n=30A357985
• Infinite triangle T(n, k), n, k >= 0, read and filled by rows the greedy way with distinct integers such that for any n, k >= 0, T(n, k) + T(n+1, k) + T(n+1, k+1) = 0; each term is minimal in absolute value and in case of a tie, preference is given to the positive value.at n=43A361442