26012

Appears in sequences

• a(n) = n-th centered n-gonal number.at n=37A100119
• a(n) = A000041(n) - A032741(n).at n=38A167934
• Sum of the first k-1 numbers in the k-th column of the natural number array A000027, by antidiagonals.at n=28A185788
• Number of 10 X 2 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2*n^2 (number of collections of 10 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).at n=13A192711
• Number of (4+1)X(n+1) 0..1 arrays with every 2X2 subblock ne-sw antidiagonal difference unequal to its neighbors horizontally and nw+se diagonal sum unequal to its neighbors vertically.at n=13A253701
• a(n) = Sum_{d|n} d^2 * (d+1)/2.at n=36A278403
• Numbers k such that (5*10^k - 107)/3 is prime.at n=20A281641
• The number of overpartitions of n whose Frobenius symbols have only positive parts in the top row.at n=28A347207