OFFSET
1,3
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Triangular Number
MATHEMATICA
lmt = 1050; t = PolygonalNumber[3, #] & /@ Range[0, Sqrt[ 2lmt]]; f[n_] := Select[ Times @@@ Partition[t, n +1, 1], # < lmt &]; lst = {}; k = 0; While[f@k != {}, lst = Join[lst, f@k]; k++]; Union@lst (* Robert G. Wilson v, Apr 16 2020 *)
PROG
(PARI) list(lim)=if(lim<1, return(if(lim<0, [], [0]))); my(v=List([0, 1]), t=1, m=2); lim\=1; while(t<=lim, listput(v, t); t=m*m++/2); for(e=1, m, for(i=3, m-e, t=factorback(Vec(v[i..i+e])); if(t>lim, break); listput(v, t))); Set(v) \\ Charles R Greathouse IV, Apr 16 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Apr 14 2020
STATUS
approved