A382831 a(n) is the n-th n-almost-prime that is a partial sum of the sequence of n-almost-primes.
2, 10, 964, 1804, 7820, 48120, 830817, 4895208, 11308160, 162802560, 394129476, 3763612800, 19823090472, 1018716103620, 9744542956800, 3989325082624, 329306801920000, 2978224618328064, 11804664377696256, 128906665137012736
Offset: 1
Keywords
Examples
The first three members of A086062 that are 3-almost-primes are 8 = 2^3, 20 = 2^2 * 5 = 8 + 12, and 964 = 2^2 * 241 = 8 + 12 + 18 + ... + 92, so a(3) = 964.
Programs
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Maple
f:= proc(n) uses priqueue; local pq,t,s,x,p,i,count; initialize(pq); insert([-2^n,2$n],pq); s:= 0; count:= 0: do t:= extract(pq); x:= -t[1]; s:= s + x; if numtheory:-bigomega(s) = n then count:= count+1; if count = n then return s fi fi; p:= nextprime(t[-1]); for i from n+1 to 2 by -1 while t[i] = t[-1] do insert([t[1]*(p/t[-1])^(n+2-i), op(t[2..i-1]), p$(n+2-i)], pq) od; od end proc: map(f, [$1..20]);