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A063981
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Numbers n such that t(n) = sigma(n) - n, where t(n) = A008472(n+1) - A008472(n).
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0
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2, 4, 9, 16, 81, 85, 256, 931, 65536, 4599097, 6309263, 16905401, 43046721, 54116239, 68229263, 98643563, 208288271, 222933913, 226461649, 230893123, 280399957, 381001633, 412016873, 417814973, 485674237, 620336281, 736284077
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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MATHEMATICA
| a = 0; b = 0; Do[a = b; b = Apply[ Plus, Transpose[ FactorInteger[n + 1]] [[1]]]; If[ b - a == DivisorSigma[1, n] - n, Print[n]], {n, 1, 2*10^7} ]
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CROSSREFS
| Cf. A008472, A001065.
Sequence in context: A056336 A203318 A060401 * A131095 A136379 A065026
Adjacent sequences: A063978 A063979 A063980 * A063982 A063983 A063984
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KEYWORD
| nonn
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AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Sep 05 2001
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 05 2001
a(14)-a(27) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Oct 13 2009
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