experimental-projects/oeis-research/Ilya Gutkovskiy/Smallest square pyramidal number with exactly n distinct prime factors/prog.sf

#!/usr/bin/ruby

# a(n) is the smallest square pyramidal number with exactly n distinct prime factors.
# https://oeis.org/A359229

# Previously known terms:
#   1, 5, 14, 30, 1785, 6930, 149226, 3573570, 139223370, 3708968340, 62366724420, 2279301054030, 1348519628145690, 27928822496705130, 1558931949520935990, 430616881400429491950, 161887663616926971163440

#`(

# PARI/GP program:
a(n) = for(k=1, oo, my(t=(k*(k+1)*(2*k + 1))\6); if(omega(t) == n, return(t))); \\ ~~~~

)

func a(n) {
    for k in (1..Inf) {
        if (pyramidal(k, 4).is_omega_prime(n)) {
            return pyramidal(k, 4)
        }
    }
}

for n in (1..100) {
    say "a(#{n}) = #{a(n)}"
}

__END__
a(1) = 5
a(2) = 14
a(3) = 30
a(4) = 1785
a(5) = 6930
a(6) = 149226
a(7) = 3573570
a(8) = 139223370
a(9) = 3708968340
a(10) = 62366724420
a(11) = 2279301054030
a(12) = 1348519628145690
a(13) = 27928822496705130
a(14) = 1558931949520935990
a(15) = 430616881400429491950