OFFSET

1,3

COMMENTS

The "smallest set of n distinct numbers" is not a well-defined term in the definition. Why is row 5 "1,2,3,6,8" but not "1,2,4,6,7"? Why is row 7 "1,2,3,4,5,8,12" but not "1,2,4,5,6,8,9"? - R. J. Mathar, Nov 12 2006

EXAMPLE

Triangle begins:

1;

1, 3;

1, 4, 7;

1, 3, 5, 7;

1, 2, 3, 6, 8;

1, 5, 7, 11, 13, 17;

1, 2, 3, 4, 5, 8, 12;

...

PROG

(PARI) row(n) = {my(m=n*(n-1)/2, v); forstep(k=m+n/(2-n%2), oo, n, v=List([]); for(i=2, k-m, if(gcd(n, i)==1, listput(v, i))); if(#v>n-2, forsubset([#v, n-1], w, if(r=1+sum(i=1, n-1, v[w[i]])==k, return(concat(1, vector(n-1, i, v[w[i]]))))))); } \\ Jinyuan Wang, May 24 2020

CROSSREFS

KEYWORD

AUTHOR

Amarnath Murthy, Mar 27 2003

EXTENSIONS

New definition proposed by Omar E. Pol, Mar 24 2008, in an attempt to answer R. J. Mathar's questions.

Name corrected and more terms from Jinyuan Wang, May 24 2020

STATUS

approved