OFFSET
1,2
COMMENTS
a(n) is > the n-th triangular number. Conjecture: There are no composite members.
PROG
(PARI) a(n) = {my(m=n*(n-1)/2, v); for(k=m+n, oo, v=List([1]); for(i=2, k-m, if(gcd(k, i)==1, listput(v, i))); if(#v>=n, forsubset([#v, n], w, if(sum(i=1, n, v[w[i]])==k, return(k))))); } \\ Jinyuan Wang, May 23 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Mar 27 2003
EXTENSIONS
a(7)-a(9) from R. J. Mathar, Mar 23 2007
More terms from Jinyuan Wang, May 23 2020
STATUS
approved