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Search: id:A065816
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| A065816 |
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Alternating sum of digits of n^2 = 0. |
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+0
1
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| 11, 22, 33, 55, 66, 88, 99, 110, 121, 132, 165, 198, 209, 220, 231, 242, 264, 319, 330, 374, 385, 429, 451, 462, 484, 495, 506, 517, 528, 550, 561, 583, 605, 616, 649, 660, 671, 682, 715, 737, 748, 814, 836, 847, 880, 891, 902, 913, 924, 935, 957, 990
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Harry J. Smith, Table of n, a(n) for n=1,...,1000
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MATHEMATICA
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f[n_] := Block[ {d = Reverse[ IntegerDigits[ n]], k = l = 1, s = 0}, l = Length[d]; While[ k <= l, s = s - (-1)^k*d[[k]]; k++ ]; Return[s]]; Select[ Range[10^3], f[ #^2] == 0 & ]
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PROGRAM
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(PARI) SumAD(x)= { local(a=1, s=0); while (x>9, s+=a*(x-10*(x\10)); x\=10; a=-a); return(s + a*x) } { n=0; for (m=1, 10^9, if (SumAD(m^2) == 0, write("b065816.txt", n++, " ", m); if (n==1000, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 31 2009]
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CROSSREFS
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Cf. A065796.
Sequence in context: A059544 A070022 A004940 this_sequence A101145 A109016 A084025
Adjacent sequences: A065813 A065814 A065815 this_sequence A065817 A065818 A065819
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 06 2001
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