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%I #10 Jun 14 2022 14:11:12
%S 0,0,1,3,5,13,27,59,125,257,534,1094,2244,4607,9407,19164,38939,79154,
%T 160473,325213,658940,1332598,2694009,5440236,10973874,22135366,
%U 44644593,89989907,181374472,365371286,734959945
%N The number of squarefree abundant numbers whose largest prime divisor is prime(n).
%C For n >= 3 we have a(n) >= 2^(n-3) as all squarefree numbers whose largest prime divisor are prime(n) that are a multiple of 6*prime(n) are abundant. - _David A. Corneth_, Jun 13 2022
%e n prime(n) a(n) terms k of A087248 with A006530(k) = prime(n)
%e - -------- ---- ---------------------------------------------
%e 1 2 0 -
%e 2 3 0 -
%e 3 5 1 30
%e 4 7 3 42, 70, 210
%e 5 11 5 66, 330, 462, 770, 2310
%t a[n_] := Count[Prime[n] * Divisors[Product[Prime[i], {i, 1, n - 1}]], _?(SquareFreeQ[#] && DivisorSigma[-1, #] > 2 &)]; Array[a, 15]
%Y Cf. A005117, A006530, A087248, A354950.
%K nonn,more
%O 1,4
%A _Amiram Eldar_, Jun 13 2022