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 A066688 Numbers n such that p(n) is congruent to n mod sigma(n), where p(n) denotes the n-th prime. 0
 1, 5, 13, 31, 299, 667, 3805, 15965, 74053, 274483, 10553437, 19329979, 71074261, 179992919, 264401891, 296059565, 8200981757, 22718360827, 24163572401 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(20) > 10^12. [From Donovan Johnson, Mar 14 2010] LINKS Table of n, a(n) for n=1..19. EXAMPLE p(5) = 11 is congruent to 5 mod sigma(5) = 6; so 5 is a term of the sequence. MATHEMATICA Select[ Range[ 1, 10^6 ], Mod[ #, DivisorSigma[ 1, # ] ] == Mod[ Prime[ # ], DivisorSigma[ 1, # ] ] & ] Select[ Range[ 1, 4 10^7 ], # == Mod[ Prime[ # ], DivisorSigma[ 1, # ]] & ] CROSSREFS Sequence in context: A147424 A146057 A062403 * A046789 A271902 A272539 Adjacent sequences: A066685 A066686 A066687 * A066689 A066690 A066691 KEYWORD nonn AUTHOR Joseph L. Pe, Jan 11 2002 EXTENSIONS More terms from Robert G. Wilson v, Jan 13 2002 a(13)-a(19) from Donovan Johnson, Mar 14 2010 STATUS approved

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Last modified October 2 14:06 EDT 2023. Contains 365837 sequences. (Running on oeis4.)