A071977 Triangle in which first row is {1}; to get n-th row take first n numbers greater than last number in previous row which are relatively prime to n.
1, 3, 5, 7, 8, 10, 11, 13, 15, 17, 18, 19, 21, 22, 23, 25, 29, 31, 35, 37, 41, 43, 44, 45, 46, 47, 48, 50, 51, 53, 55, 57, 59, 61, 63, 65, 67, 68, 70, 71, 73, 74, 76, 77, 79, 81, 83, 87, 89, 91, 93, 97, 99, 101, 103, 104, 105, 106, 107, 108, 109, 111, 112, 113, 114, 115
Offset: 1
Examples
Triangle begins 1; 3 5; 7 8 10; 11 13 15 17; 18 19 21 22 23; 25 29 31 35 37 41; ....
Links
- Reinhard Zumkeller, Rows n=1..120 of triangle, flattened
Programs
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Haskell
a071977 n k = a071977_tabl !! (n-1) !! (k-1) a071977_row n = a071977_tabl !! (n-1) a071977_tabl = f 1 [1..] where f k xs = ys : f (k+1) (dropWhile (<= last ys) xs) where ys = take k $ filter ((== 1) . (gcd k)) xs -- Reinhard Zumkeller, Jan 18 2012 -
Mathematica
a = {1}; k = 2; Do[i = 1; While[i < n + 1, If[ GCD[k, n] == 1, a = Append[a, k]; i++ ]; k++ ], {n, 2, 12}]; a
Extensions
Edited by Robert G. Wilson v, Jun 28 2002
Comments