A062036 - OEIS

%I #18 Aug 02 2022 09:20:22

%S 88,189,198,246,264,426,462,624,642,819,891,918,981,1247,1274,1344,

%T 1427,1434,1443,1472,1724,1742,2147,2174,2226,2262,2417,2471,2622,

%U 2714,2741,3144,3414,3441,4127,4134,4143,4172,4217,4271,4314,4341,4413,4431

%N Positive numbers whose product of digits is four times their sum.

%H Harry J. Smith, <a href="/A062036/b062036.txt">Table of n, a(n) for n = 1..500</a>

%e 1344 belongs to the sequence as (1*3*4*4)/(1+3+4+4) = 48/12 = 4.

%t p4sQ[n_]:=Module[{idn=IntegerDigits[n]},Times@@idn/Total[idn]==4]; Select[Range[5000],p4sQ]  (* _Harvey P. Dale_, Apr 26 2011 *)

%o (PARI) isok(n) = my(d=digits(n)); vecprod(d)==4*vecsum(d) \\ _Mohammed Yaseen_, Jul 31 2022

%o (Python)

%o from math import prod

%o def ok(n): d = list(map(int, str(n))); return prod(d) == 4*sum(d)

%o print([k for k in range(1, 5000) if ok(k)]) # _Michael S. Branicky_, Jul 31 2022

%Y Cf. A011540, A034710, A062034, A062035, A062382, A062037, A062384, A062040, A062041, A062043, A062045.

%K nonn,base,easy

%O 1,1

%A _Amarnath Murthy_, Jun 27 2001

%E More terms from Larry Reeves (larryr(AT)acm.org), Jul 06 2001

%E Offset corrected by _Mohammed Yaseen_, Jul 31 2022