20090

Appears in sequences

• Truncated triangular pyramid numbers: a(n) = Sum_{k=9..n} (k*(k+1)/2 - 45).at n=41A051943
• Number of symmetric types of (3,2n)-hypergraphs under action of complementing group C(3,2).at n=39A055780
• Non-palindromic number and its reversal are both multiples of 14.at n=36A062913
• Numbers k such that numerator(Bernoulli(2*k)/(2*k)) is different from numerator(Bernoulli(2*k)/(2*k*(2*k-1))).at n=77A090495
• First monotonically increasing sequence such that erasing the first and last digit of each term and concatenating what is left results in the concatenation of all terms of the sequence.at n=40A106004
• a(n) = 2*n*(6*n-1).at n=41A126964
• a(n) = 7*A000330(n).at n=20A169607
• Numbers m such that the sum of the first k odd primes = m-th odd prime.at n=22A179321
• Number of nondecreasing -n..n vectors of length 3 whose dot product with some other -n..n vector equals 3.at n=24A226342
• a(n) = 7*binomial(9*n+7,n)/(9*n+7).at n=4A234510
• Number of partitions of n into 7 parts such that every i-th smallest part (counted with multiplicity) is different from i.at n=34A244243
• Expansion of exp( Sum_{n>=1} -sigma(8*n)*x^n/n ) in powers of x.at n=24A283168
• Number of Sós permutations of {0,1,...,n}.at n=39A330503
• a(n) = (k+1)*n + k*(k+1)/2, where k = A332542(n).at n=38A332544
• Number of compositions of n whose run-lengths are either strictly increasing or strictly decreasing.at n=41A333191
• Expansion of the o.g.f. (2*x^2 + 3*x + 2)*x/((x + 1)^2*(x - 1)^4).at n=40A342397
• Multiplicative orders of 2+-i modulo p == 3 (mod 4) that are congruent to 2 modulo 4.at n=4A385218
• Number of solid partitions of n with 4 parts.at n=41A387997