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 A176170 Smallest prime-factor of n-th product of 4 distinct primes. 4
 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS FactorInteger[210]=2*3*5*7,... LINKS Antti Karttunen, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A020639(A046386(n)). - Antti Karttunen, Dec 06 2017 MATHEMATICA f0[n_]:=Last/@FactorInteger[n]=={1, 1, 1, 1}; f1[n_]:=Min[First/@FactorInteger[n]]; f2[n_]:=First/@FactorInteger[n][[2, 1]]; f3[n_]:=First/@FactorInteger[n][[3, 1]]; f4[n_]:=Max[First/@FactorInteger[n]]; lst={}; Do[If[f0[n], AppendTo[lst, f1[n]]], {n, 0, 2*7!}]; lst PROG (PARI) n=0; i=0; while(i<10000, n++; if((4 == bigomega(n))&&(4 == omega(n)), i++; write("b176170.txt", i, " ", factor(n)[1, 1]))); \\ Antti Karttunen, Dec 06 2017 CROSSREFS Cf. A020639, A046386, A006881, A007304, A070647, A096916, A096917, A096918, A096919 Sequence in context: A105514 A214081 A194338 * A062153 A217693 A204560 Adjacent sequences: A176167 A176168 A176169 * A176171 A176172 A176173 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Apr 10 2010 STATUS approved

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Last modified November 26 17:30 EST 2022. Contains 358362 sequences. (Running on oeis4.)