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%I #10 Jan 02 2023 12:30:46
%S 0,1,11,111,2,12,112,1112,22,3,13,113,222,23,123,1123,4,14,33,133,24,
%T 124,233,1233,224,5,15,115,1115,25,125,1125,44,144,35,135,6,16,116,
%U 1116,26,45,145,335,226,36,136,1136,444,7,17,117,46,27,127,1127,246
%N Smallest number whose sum of squares of digits is n.
%H Zak Seidov, <a href="/A055016/b055016.txt">Table of n, a(n) for n = 0..600</a>
%H E. Angelini, <a href="http://list.seqfan.eu/oldermail/seqfan/2015-June/014998.html">Sum of squares -- and a concatenation</a>, SeqFan list, June 23, 2015.
%o (PARI) A055016(n,q=9,m)={ n>1||return(n); forstep(q=min(sqrtint(n),q),1,-1, m && n \ q^2 * #Str(q) > #Str(m) && break; t=eval(Str(A055016(n-q^2,q),q)); (!m || t<m) && m=t); m } \\ _M. F. Hasler_, Jun 24 2015
%Y Cf. A003132 is inverse in sense that n=A003132(a(n)), though not necessarily a(A003132(n)).
%K base,nonn
%O 0,3
%A _Henry Bottomley_, May 31 2000
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