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Search: id:A054411
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| A054411 |
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If n = p_1^c_1 *p_2^c_2 *p_3^c_3...*p_k^c_k, where c's are positive integers and p's are distinct primes, then sum{j=1 to k}[p_j] =sum{j=1 to k}[c_j]. |
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9
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| 1, 4, 27, 48, 72, 108, 162, 320, 800, 1792, 2000, 3125, 3840, 5000, 5760, 6272, 8640, 9600, 10935, 12500, 12960, 14400, 18225, 19440, 21504, 21600, 21952, 24000, 29160, 30375, 31250, 32256, 32400, 36000, 43740, 45056, 48384, 48600, 50625
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Numbers where the sum of distinct prime factors equals the sum of exponents in prime factorization, A008472(n)=A001222(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Mar 08 2002
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EXAMPLE
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320 is included because 320 = 2^6 *5^1 and 2+5 = 6+1.
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PROGRAM
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(PARI) for(n=1, 10^6, if(bigomega(n)==sumdiv(n, d, isprime(d)*d), print1(n, ", ")))
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CROSSREFS
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Cf. A054412, A068935, A068936, A068937, A068938.
Sequence in context: A068349 A129204 A082872 this_sequence A051506 A033663 A141091
Adjacent sequences: A054408 A054409 A054410 this_sequence A054412 A054413 A054414
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), May 09 2000
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