A048348 a(n)^2 is the smallest square containing exactly n 3's.

6, 56, 586, 1156, 11547, 57735, 559769, 1197219, 6582806, 36514844, 350903624, 1798230611, 1825769244, 48304278624, 11547014044, 577333277556, 1527394295306, 6582576498844, 57465931849517

Offset

1,1

Comments

a(20) > 10^14. - Giovanni Resta, Jul 27 2018

Links

Table of n, a(n) for n=1..19.

Eric Weisstein's World of Mathematics, Square Number

Mathematica

a[n_] := Block[{k=1}, While[DigitCount[k^2, 10, 3] != n, k++]; k]; Array[a, 6] (* Giovanni Resta, Jul 27 2018 *)

Crossrefs

Cf. A036510, A034982.

Sequence in context: A092655 A099140 A371739 * A227384 A199755 A025749

Adjacent sequences: A048345 A048346 A048347 * A048349 A048350 A048351

Keyword

nonn,base,more

Author

Patrick De Geest, Mar 15 1999

Extensions

More terms from Jon E. Schoenfield, Jan 11 2009

a(18)-a(19) from Giovanni Resta, Jul 27 2018

Status

approved