A359014 a(n) is the index of the smallest n-gonal number with exactly n prime factors (counted with multiplicity).
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
Links
- Eric Weisstein's World of Mathematics, Prime Factor
- Eric Weisstein's World of Mathematics, Polygonal Number
Programs
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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
Extensions
a(29)-a(34) from Daniel Suteu, Dec 12 2022