A078448 Triangle T(n,k) for 1 <= n, 1 <= k <= n read by rows: T(1,1) = 1; for n > 1: T(n,1) = T(n-1,n-1) + 1; for n > 1 and k <=n: T(n,k) = smallest number > T(n,k-1) which is relatively prime to T(n,j) for 1 <= j < k.

1, 2, 3, 4, 5, 7, 8, 9, 11, 13, 14, 15, 17, 19, 23, 24, 25, 29, 31, 37, 41, 42, 43, 47, 53, 55, 59, 61, 62, 63, 65, 67, 71, 73, 79, 83, 84, 85, 89, 97, 101, 103, 107, 109, 113, 114, 115, 119, 121, 127, 131, 137, 139, 149, 151, 152, 153, 155, 157, 161, 163, 167, 169, 173

Offset

1,2

Links

Table of n, a(n) for n=1..64.

Example

1
2 3
4 5 7
8 9 11 13
14 15 17 19 23
24 25 29 31 37 41
42 43 47 53 55 59 61
62 63 65 67 71 73 79 83
...

Prog

(PARI) {s=[1]; for (n=2, 12, for(j=1, n-1, print1(s[j], ", ")); a=s[n-1]; s=[a+1]; for(j=2, n, k=s[j-1]+1; c=1; while(c>0, b=1; for(i=1, matsize(s)[2], if(gcd(k, s[i])>1, b=0)); if(b==0, k++, c=0)); s=concat(s, k)))}

Crossrefs

Cf. A078447, A078449, A078450.

Sequence in context: A097904 A094387 A050744 * A212289 A191840 A376371

Adjacent sequences: A078445 A078446 A078447 * A078449 A078450 A078451

Keyword

nonn,tabl

Author

Amarnath Murthy, Nov 27 2002

Extensions

Edited, corrected and extended by Klaus Brockhaus, Dec 10 2002

Status

approved