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A333967 Subsequence of A071395. The extra constraint is m is not a term if m*q/p is abundant where prime p|m and q is the least prime larger than p. 2
70, 2002, 3230, 4030, 5830, 8415, 8925, 20482, 32445, 45885, 51765, 83265, 107198, 131054, 133042, 178486, 206770, 253270, 253946, 258970, 270470, 310930, 330310, 334305, 362710, 442365, 474045, 497835, 513890, 544310, 567765, 589095, 592670, 602175, 617265, 631670, 654675 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

David A. Corneth, Table of n, a(n) for n = 1..1317

EXAMPLE

70 is in the sequence as it's abundant. Its prime factorization is 2 * 5 * 7. Each of 3 * 5 * 7, 2 * 7 * 7 and 2 * 5 * 11 are deficient and no divisor of 70 is in this sequence.

MATHEMATICA

primabQ[n_] := DivisorSigma[1, n] > 2n && AllTrue[Most @ Divisors[n], DivisorSigma[1, #] < 2# &]; seqQ[n_] := Module[{f = FactorInteger[n]}, p = f[[;; , 1]]; e = f[[;; , 2]]; q = NextPrime[p]; AllTrue[n*(q/p), DivisorSigma[1, #] <= 2# &]]; Select[Range[10^5], primabQ[#] && seqQ[#] &] (* Amiram Eldar, Jul 05 2020 *)

CROSSREFS

Cf. A071395, A071927, A335557.

Sequence in context: A006296 A047835 A133312 * A093757 A163022 A271031

Adjacent sequences: A333964 A333965 A333966 * A333968 A333969 A333970

KEYWORD

nonn

AUTHOR

David A. Corneth, Jul 05 2020

STATUS

approved

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Last modified November 28 02:09 EST 2022. Contains 358406 sequences. (Running on oeis4.)