A351704 Sums of the ascending diagonals of the triangle A162609.
1, 1, 2, 3, 7, 10, 20, 26, 45, 55, 86, 101, 147, 168, 232, 260, 345, 381, 490, 535, 671, 726, 892, 958, 1157, 1235, 1470, 1561, 1835, 1940, 2256, 2376, 2737, 2873, 3282, 3435, 3895, 4066, 4580, 4770, 5341, 5551, 6182, 6413, 7107, 7360, 8120, 8396, 9225, 9525, 10426, 10751, 11727, 12078, 13132, 13510, 14645
Offset: 0
Keywords
Examples
a(4) = (64 + 8 + 12)/12 = 7 a(5) = (250 - 75 + 50 + 15)/24 = 10.
Links
- Eddie Gutierrez, The Wheel Octagon Triangle - Ascending Diagonals (Part VIIIb)
Crossrefs
Cf. A162609.
Programs
-
C
// Calculates and prints out the triangle and terms of ascending diagonals (on first line). To get more terms increment j. #include
int main() { int n, j=8, k, C, F1, F2,s; F1=1; F2=1; printf("%d ", F1); printf("%d ", F2); for (s=0;s<=j;s++) { F1=F1 + 2*s*s + 2*s + 1; F2=F2 + 2*s*s + 3*s + 2; printf("%d ", F1); printf("%d ", F2); } printf("\n"); return 0; }
Formula
a(n) = (n^3 + 2*n + 12)/12, for even n.
a(n) = (2*n^3 - 3*n^2 + 10*n + 15)/24, for odd n.
Comments