OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
MATHEMATICA
Table[Times @@ MapIndexed[(Prime@ First@ #2)^#1 &, #] &@ If[Length@ # == 1 && #[[1, 1]] == 1, {0}, Reverse@ Sort@ #[[All, -1]]] &@ FactorInteger[ (n^2 - n)/2], {n, 2, 87}] (* Michael De Vlieger, Nov 21 2016 *)
PROG
(PARI) a(n)=my(f=vecsort(factor(n*(n+1)/2)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]) \\ Charles R Greathouse IV, Feb 03 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 19 2016
STATUS
approved