Search: id:A082021 Results 1-1 of 1 results found. %I A082021 %S A082021 7,23,131,47,643,2459,2000807,503347241 %N A082021 a(0) = 7; for n > 0, a(n) is the greatest prime factor of PP(PP(a(n-1)))*a(n-1)+2 where PP(n) is an abbreviation for PreviousPrime(n). %t A082021 NestWhileList[FactorInteger[2+#*Prime[PrimePi[ # ]-2]][[ -1,1]] &, 7, True, 8] - T. D. Noe (noe(AT)sspectra.com), Nov 15 2006 %Y A082021 Cf. A082032, A031441, A031442. %Y A082021 Sequence in context: A064640 A064639 A064638 this_sequence A080082 A158954 A056205 %Y A082021 Adjacent sequences: A082018 A082019 A082020 this_sequence A082022 A082023 A082024 %K A082021 nonn %O A082021 0,1 %A A082021 Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp), May 10 2003 %E A082021 Description corrected by Rick L. Shepherd (rshepherd2(AT)hotmail.com), Dec 19 2004 %E A082021 Corrected by T. D. Noe (noe(AT)sspectra.com), Nov 15 2006 Search completed in 0.001 seconds