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A359014
a(n) is the index of the smallest n-gonal number with exactly n prime factors (counted with multiplicity).
1
7, 4, 11, 50, 60, 22, 315, 264, 1295, 256, 315, 4480, 4727, 2634, 25123, 8192, 15903, 18432, 314315, 368640, 1859975, 95326, 2068659, 3145728, 2181039, 1028412, 23612379, 83886080, 18512791, 72421650, 536870912, 251658240
OFFSET
3,1
LINKS
Eric Weisstein's World of Mathematics, Prime Factor
Eric Weisstein's World of Mathematics, Polygonal Number
PROG
(PARI) a(n) = if(n<3, return()); for(k=1, oo, my(t=(k*(n*k - n - 2*k + 4))\2); if(bigomega(t) == n, return(k))); \\ Daniel Suteu, Dec 12 2022
CROSSREFS
Sequence in context: A335166 A165415 A069199 * A138339 A107827 A070406
KEYWORD
nonn,more
AUTHOR
Ilya Gutkovskiy, Dec 12 2022
EXTENSIONS
a(29)-a(34) from Daniel Suteu, Dec 12 2022
STATUS
approved