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A048977
Primes arising in A048969.
0
3, 7, 13, 19, 31, 61, 127, 127, 331, 307, 307, 631, 1801, 1723, 3169, 1093, 1723, 3571, 1093, 3221, 5419, 3541, 3541, 8269, 5113, 5113, 13267, 8011, 8011, 16651, 10303, 19441, 10303, 24571, 17293, 17293, 28057, 30103, 55897, 28057, 59221, 30103, 8191, 19531
OFFSET
1,1
MATHEMATICA
p[n_]:=Module[{c=DivisorSigma[1, n]/DivisorSigma[0, n]}, If[PrimeQ[c], c, 0]]; nn=62000; With[{comps=Complement[Range[nn], Prime[Range[PrimePi[nn]]]]}, Select[ p/@comps, #!=0&]] (* Harvey P. Dale, Feb 19 2012 *)
CROSSREFS
Sequence in context: A023217 A106077 A216515 * A216518 A342822 A154650
KEYWORD
nonn
EXTENSIONS
More terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Jun 17 2001
More terms from Sean A. Irvine, Jul 16 2021
STATUS
approved