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A081515
Sum of terms in n-th row of A081517.
4
1, 3, 7, 11, 17, 23, 29, 37, 47, 59, 67, 79, 97, 107, 127, 137, 157, 173, 191, 211, 233, 257, 277, 307, 331, 353, 379, 409, 439, 467, 499, 541, 563, 599, 631, 673, 709, 743, 787, 821, 863, 907, 947, 991, 1039, 1087, 1129, 1181, 1229, 1277, 1327, 1381, 1433, 1487
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
Sequence in context: A090513 A285600 A191050 * A289750 A184856 A023234
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