

A055016


Smallest number whose sum of squares of digits is n.


4



0, 1, 11, 111, 2, 12, 112, 1112, 22, 3, 13, 113, 222, 23, 123, 1123, 4, 14, 33, 133, 24, 124, 233, 1233, 224, 5, 15, 115, 1115, 25, 125, 1125, 44, 144, 35, 135, 6, 16, 116, 1116, 26, 45, 145, 335, 226, 36, 136, 1136, 444, 7, 17, 117, 46, 27, 127, 1127, 246
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,3


LINKS

Zak Seidov, Table of n, a(n) for n = 0..600
E. Angelini, Sum of squares  and a concatenation, SeqFan list, June 23, 2015.


PROG

(PARI) A055016(n, q=9, m)={ n>1return(n); forstep(q=min(sqrtint(n), q), 1, 1, m && n \ q^2 * #Str(q) > #Str(m) && break; t=eval(Str(A055016(nq^2, q), q)); (!m  t<m) && m=t); m } \\ M. F. Hasler, Jun 24 2015


CROSSREFS

Cf. A003132 is inverse in sense that n=A003132(a(n)), though not necessarily a(A003132(n)).
Sequence in context: A185535 A281601 A266513 * A259372 A004287 A061493
Adjacent sequences: A055013 A055014 A055015 * A055017 A055018 A055019


KEYWORD

base,nonn


AUTHOR

Henry Bottomley, May 31 2000


STATUS

approved



