80921

Appears in sequences

• Number of nodes in regular n-gon with all diagonals drawn.at n=39A007569
• a(1) = 1, then multiply, add and subtract 2, 3, 4; 5, 6, 7; ... in that order.at n=17A077382
• a(n) = 70*n^2 + 1.at n=34A158734