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A360777
a(n) is the index of the least n-gonal number that is the sum of two or more consecutive nonzero n-gonal numbers in more than one way, or -1 if no such number exists.
1
9, 160, 143, 2679, 19933, 115248, 45, 1995
OFFSET
2,1
COMMENTS
a(10)>2000000, a(11)=24375, a(12)=133307113, a(13)=6715891, a(16)=189308, a(20)=9009. - Sean A. Irvine, Mar 24 2023
LINKS
Eric Weisstein's World of Mathematics, Polygonal Number
CROSSREFS
Sequence in context: A377447 A230180 A361047 * A309472 A060348 A365016
KEYWORD
nonn,more
AUTHOR
Ilya Gutkovskiy, Feb 20 2023
STATUS
approved