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A229153
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Numbers of the form c * m^2, where m > 0 and c is composite and squarefree.
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7
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6, 10, 14, 15, 21, 22, 24, 26, 30, 33, 34, 35, 38, 39, 40, 42, 46, 51, 54, 55, 56, 57, 58, 60, 62, 65, 66, 69, 70, 74, 77, 78, 82, 84, 85, 86, 87, 88, 90, 91, 93, 94, 95, 96, 102, 104, 105, 106, 110, 111, 114, 115, 118, 119, 120, 122, 123, 126, 129, 130, 132, 133, 134, 135, 136, 138, 140, 141, 142, 143, 145, 146, 150
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OFFSET
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1,1
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COMMENTS
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Subsequence of A048943. According to Gerard P. Michon, one of the criteria for N to belong to A048943 is that it has at least two prime factors with odd multiplicities. By definition, the composite factor c in any term of A229153 conforms to this criterion.
From a(1) to a(63), identical to the given terms of A119847, except for the single term a(55) = 120.
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LINKS
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PROG
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(PARI) iscomposite(n)={if(!isprime(n)&&n!=1, return(1)); }
test(n)={if(iscomposite(core(n)), return(1)); }
for(n=1, 200, if(test(n)==1, print1(n", ")))
(PARI) lista(nn) = {for(n=1, nn, if(!ispseudoprime(core(n)) && !issquare(n), print1(n, ", "))); } \\ Altug Alkan, Feb 04 2016
(PARI) list(lim)=my(v=List()); forsquarefree(c=6, lim\=1, if(#c[2]~ > 1, for(m=1, sqrtint(lim\c[1]), listput(v, c[1]*m^2)))); Set(v) \\ Charles R Greathouse IV, Jan 09 2022
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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