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A061090 Squares the sum of the squares of whose digits are squares.

%I A061090 #21 Jul 02 2025 16:02:01
%S A061090 1,4,9,100,400,676,841,900,1444,4225,10000,24025,40000,42025,42436,
%T A061090 43264,66049,67600,84100,90000,109561,119716,144400,155236,239121,
%U A061090 244036,248004,252004,335241,355216,362404,373321,422500,643204,664225
%N A061090 Squares the sum of the squares of whose digits are squares.
%C A061090 Contains 10^(2k) for all k.
%C A061090 More generally, if k is in this sequence so is 100k. - _Charles R Greathouse IV_, Sep 20 2012
%D A061090 A. Murthy, Smarandache Pythagoras additive square sequence (to be published in Smarandache Notions Journal).
%H A061090 Charles R Greathouse IV, <a href="/A061090/b061090.txt">Table of n, a(n) for n = 1..10000</a>
%e A061090 676 = 26^2, 6^2 + 7^2 + 6^2 = 121 = 11^2;
%e A061090 1444 = 38^2, 1^2 + 4^2 + 4^2 + 4^2 = 49 = 7^2.
%p A061090 readlib(issqr): for n from 1 to 2000 do L1 := convert(n^2, base, 10): if issqr(sum(L1[i]^2, i=1..nops(L1))) then printf(`%d,`,n^2) fi: od:
%t A061090 Select[Range[1000]^2,IntegerQ[Sqrt[Total[IntegerDigits[#]^2]]]&] (* _Harvey P. Dale_, Apr 26 2025 *)
%o A061090 (PARI) ssd(n)=n=digits(n);sum(i=1,#n,n[i]^2)
%o A061090 v=List();for(n=1,1e4,if(issquare(ssd(n^2)),listput(v,n^2))); Vec(v) \\ _Charles R Greathouse IV_, Sep 20 2012
%Y A061090 Cf. A053057.
%K A061090 nonn,base
%O A061090 1,2
%A A061090 _Amarnath Murthy_, Apr 19 2001
%E A061090 Corrected and extended by _James Sellers_, Apr 20 2001