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 A257146 Primitive non-solvable numbers: elements of A056866 not divisible by any earlier term. 4
 60, 168, 1092, 2448, 5616, 6072, 25308, 29120, 32736, 39732, 51888, 74412, 150348, 194472, 285852, 546312, 612468, 1285608, 1934868, 2097024, 2165292, 2588772, 3594432, 3822588, 5848428, 6324552, 7174332, 8487168, 9095592, 10626828, 11332452, 12576732, 14467068, 15331992, 15927348 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A number is solvable if and only if it is a positive multiple of a member of this sequence. There is 1 member of this sequence up to 10^2, 2 up to 10^3, 6 up to 10^4, 12 up to 10^5, 17 up to 10^6, 29 up to 10^7, 49 up to 10^8, 89 up to 10^9, 169 up to 10^10, 321 up to 10^11, 616 up to 10^12, 1188 up to 10^13, 2351 up to 10^14, 4679 up to 10^15, 9350 up to 10^16, 18866 up to 10^17, 38157 up to 10^18, 77534 up to 10^19, 158048 up to 10^20, 323358 up to 10^21, 663159 up to 10^22, and 1363304 up to 10^23. - Charles R Greathouse IV, Sep 16 2015 LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 FORMULA a(n) >> n^3 log^3 n. - Charles R Greathouse IV, Apr 20 2015 PROG (PARI) list(lim)={   my(v=List(), t);   forprime(p=2, ,     t=(4^p-1)<lim, break);     listput(v, t)   );   forprime(p=3, ,     t=3^p*(9^p-1)/2;     if(t>lim, break);     listput(v, t)   );   forprime(p=7, ,     t=p*(p^2-1)/2;     if(t>lim, break);     listput(v, t)   );   forprime(p=3, ,     t=4^p*(4^p+1)*(2^p-1);     if(t>lim, break);     listput(v, t)   );   if(lim>=5616, listput(v, 5616));   v=Set(v);   for(i=1, #v,     if(v[i]==60 && i>1, next); \\ see below     for(j=i+1, #v,       if(v[j]%v[i]==0, v[j]=60) \\ delete values by setting to v[1]     )   );   Set(v); \\ remove duplicates to combine all 60s } CROSSREFS Cf. A056866. Sequence in context: A330586 A119630 A216480 * A291549 A259946 A249911 Adjacent sequences:  A257143 A257144 A257145 * A257147 A257148 A257149 KEYWORD nonn AUTHOR Charles R Greathouse IV, Apr 16 2015 STATUS approved

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Last modified October 1 08:39 EDT 2020. Contains 337442 sequences. (Running on oeis4.)