

A234004


Smallest number which is the sum of two positive triangular numbers (A000217) in at least n ways.


1



2, 16, 81, 471, 1056, 1381, 6906, 6906, 17956, 34531, 40056, 40056, 200281, 200281, 200281, 200281, 520731, 520731, 1001406, 1001406, 1482081, 1482081, 1482081, 1482081, 7410406, 7410406, 7410406, 7410406, 7410406, 7410406, 7410406, 7410406
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS



EXAMPLE

2 = 1+1; 16 = 1+15 = 6+10; 81 = 3+78 = 15+66 = 36+45.


MATHEMATICA

poly[n_, k_]:=n (n1)(k2)/2+n; nn=10^5; order=3; t2=Table[0, {nn}]; n2=Floor[(4+#+Sqrt[(4+#)^2+8 (2+#) nn])/(2 (2+#))&[order]]; Do[r=Plus@@poly[{a, b}, order]; If[r<=nn, t2[[r]]++], {a, n2}, {b, a, n2}]; t={}; n=1; While[a=Position[t2, _?(#>=n&), 1, 1]; a!={}, AppendTo[t, a[[1, 1]]]; n++]; t (* after T. D. Noe (A048610) *)


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



