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A053820
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Sum_{k=1..n, gcd(n,k) = 1} k^4.
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1
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1, 1, 17, 82, 354, 626, 2275, 3108, 7395, 9044, 25333, 17668, 60710, 50470, 88388, 103496, 243848, 129750, 432345, 266088, 497574, 497178, 1151403, 539912, 1541770, 1153724, 1900089, 1516844, 3756718, 1246568, 5273999
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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REFERENCES
| T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 48, problem 15, the function phi_4(n).
L. E. Dickson, History of the Theory of Numbers, Vol. I (Reprint 1966), p. 140.
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LINKS
| P. G. Brown, Some comments on inverse arithmetic functions, Math. Gaz. 89 (2005) 403-408.
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FORMULA
| a(n)=(6*n^4*A000010(n)+10*n^3*A023900(n)-n*A063453(n))/30 for n>1. Formula is derived from a more general formula of A. Thacker (1850), see [Dickson, Brown]. - Franz Vrabec (franz.vrabec(AT)aon.at), Aug 21 2005
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CROSSREFS
| Sequence in context: A065960 A017671 A001159 * A142059 A193046 A158528
Adjacent sequences: A053817 A053818 A053819 * A053821 A053822 A053823
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Apr 07 2000
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