OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10092 (triples with sum <= 52)
FORMULA
Terms are lexically ordered in triples by sum: 1 2 3 (sum = 6) 1 2 4 (sum = 7) 1 2 5, then 1 3 4 (two triples having sum = 8), etc.
MAPLE
f:= proc(n) local i, j;
seq(seq(op([i, j, n-i-j]), j = i+1 .. (n-i-1)/2), i=1..n/3);
end proc:
map(f, [$1..20]); # Robert Israel, May 09 2024
PROG
(PARI) a_rows(N) = [[Vec(e)+[0, 1, 2] |e<-partitions(n, , [3, 3])] |n<-[3..N+2]]; \\ Ruud H.G. van Tol, May 09 2024
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Clark Kimberling, Aug 05 2004
STATUS
approved