A350423 - OEIS

A350423

a(n) is the smallest n-gonal number which can be represented as the sum of n distinct nonzero n-gonal numbers in exactly n ways, or -1 if none exists.

%I #15 Jan 27 2022 20:57:03

%S 190,289,330,561

%N a(n) is the smallest n-gonal number which can be represented as the sum of n distinct nonzero n-gonal numbers in exactly n ways, or -1 if none exists.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a>

%e For n = 3: 190 = 1 + 36 + 153 = 15 + 55 + 120 = 21 + 78 + 91.

%Y Cf. A057145, A350405.

%K nonn,more

%O 3,1

%A _Ilya Gutkovskiy_, Dec 31 2021