A039392 Numbers whose base-9 representation has the same nonzero number of 7's and 8's.

71, 79, 152, 160, 233, 241, 314, 322, 395, 403, 476, 484, 557, 565, 575, 584, 593, 602, 611, 620, 629, 639, 640, 641, 642, 643, 644, 645, 655, 664, 673, 682, 691, 700, 709, 711, 712, 713, 714, 715, 716, 717, 800, 808, 881, 889, 962, 970, 1043, 1051

Offset

1,1

Links

Chris R. Rehmann, Table of n, a(n) for n = 1..10000

Mathematica

b9Q[n_]:=Module[{idn9=IntegerDigits[n, 9]}, Count[idn9, 7]==Count[idn9, 8]!=0]
Select[Range[1100], b9Q]  (* Harvey P. Dale, Feb 14 2011 *)

Prog

(MATLAB) x = 0:1051; d = dec2base(x, 9)-'0'; s1 = sum(d==7, 2); s2 = sum(d==8, 2); a = x(s1==s2 & s1>0); disp(regexprep(num2str(a), ' +', ', ')) % Chris R. Rehmann, Apr 14 2026

Crossrefs

Cf. A007095, A039111.

Cf. A039364, A039371, A039377, A039382, A039386, A039389, A039391.

Sequence in context: A396041 A033245 A139914 * A043215 A043995 A134936

Adjacent sequences: A039389 A039390 A039391 * A039393 A039394 A039395

Keyword

nonn,base,easy

Author

Olivier Gérard

Status

approved