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A037175
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Numbers k such that |s(k) - k| = number of primes <= k, where s(k) is sigma(k) - k.
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0
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2, 3, 15, 22, 98, 460, 5408, 21170, 243568, 3587402, 25881424, 25888784, 33305870, 61202192, 115333190, 135135182, 167241932, 788355824, 788360176, 1653570248
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OFFSET
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1,1
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COMMENTS
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a(21) > 10^11. - _Donovan Johnson,_ Aug 15 2011
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LINKS
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MAPLE
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with(numtheory):np:=0: for n from 1 to 300000 do if isprime(n) then np:=np+1 fi: if(abs(sigma(n)-2*n)=np) then printf("%d, ", n) fi od: (C. Ronaldo)
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PROG
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(PARI) np=0; for(n=1, 10000000, if(isprime(n), np=np+1); if(abs(sigma(n)-2*n)==np, print1(n, ", "))) (Ronaldo)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 30 2004
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STATUS
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approved
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