A061423 Sum of digits = 6 times number of digits.

6, 39, 48, 57, 66, 75, 84, 93, 189, 198, 279, 288, 297, 369, 378, 387, 396, 459, 468, 477, 486, 495, 549, 558, 567, 576, 585, 594, 639, 648, 657, 666, 675, 684, 693, 729, 738, 747, 756, 765, 774, 783, 792, 819, 828, 837, 846, 855, 864, 873, 882, 891, 909

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

288 is a term as the arithmetic mean of the digits is (2+8+8)/3 = 6.

Maple

F:= proc(m, s)
option remember;
# list of all m-digit numbers with sum of digits s
if s > 9*m or s < 0 then return [] fi;
if m = 1 then return [s] fi;
[seq(seq(op(map(`+`, procname(j, s-i), 10^(m-1)*i)), j=1..m-1), i=1..min(9, s))]
end proc:
seq(op(F(m, 6*m)), m=1..3); # Robert Israel, Jan 27 2016

Mathematica

Select[Range[1000], Total[IntegerDigits[#]]==6*IntegerLength[#]&] (* Harvey P. Dale, Dec 20 2014 *)

Prog

(PARI) isok(n) = {digs = digits(n, 10); return(6*#digs == sum(k=1, #digs, digs[k])); } \\ Michel Marcus, Jul 31 2013
(Magma) [n: n in [1..1000] | &+Intseq(n) eq 6*#Intseq(n)]; // Vincenzo Librandi, Jan 28 2016

Crossrefs

Cf. A061383, A061384, A061385, A061386, A061387, A061388, A061424, A061425.

Sequence in context: A096674 A241258 A366212 * A080298 A253803 A355412

Adjacent sequences: A061420 A061421 A061422 * A061424 A061425 A061426

Keyword

base,easy,nonn

Author

Amarnath Murthy, May 03 2001

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001

Status

approved