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A049627
Array T read by diagonals; T(i,j)=(i+1)*(j+1)-H(i,j), where H is the array in A049615; thus T(i,j) is the number of lattice points in rectangle having diagonal (0,0)-to-(i,j) that are visible from (i,j).
11
1, 2, 2, 2, 4, 2, 2, 5, 5, 2, 2, 6, 6, 6, 2, 2, 7, 8, 8, 7, 2, 2, 8, 9, 10, 9, 8, 2, 2, 9, 11, 12, 12, 11, 9, 2, 2, 10, 12, 15, 14, 15, 12, 10, 2, 2, 11, 14, 16, 18, 18, 16, 14, 11, 2, 2, 12, 15, 19, 19, 22, 19, 19, 15, 12, 2, 2, 13, 17, 21, 23, 24, 24, 23, 21
OFFSET
0,2
EXAMPLE
Diagonals (each starting on row 0):
{1};
{2,2};
{2,4,2};
...
Array begins:
1 2 2 2 2 2 2
2 4 5 6 7 8 9
2 5 6 8 9 11 12
2 6 8 10 12 15 16
2 7 9 12 14 18 19
2 8 11 15 18 22 24
2 9 12 16 19 24 26
PROG
(PARI) T(n, k) = (n+1)*(k+1) - sum(i=0, n, sum(j=0, k, gcd(i, j)>1));
matrix(7, 7, n, k, T(n-1, k-1)) \\ Michel Marcus, Aug 06 2021
CROSSREFS
Cf. A049615.
Sequence in context: A329586 A255336 A292929 * A278223 A368556 A134058
KEYWORD
nonn,tabl
STATUS
approved