The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A237767 Product of digits of n is a nonzero cube. 2
 1, 8, 11, 18, 24, 39, 42, 81, 88, 93, 111, 118, 124, 139, 142, 181, 188, 193, 214, 222, 241, 248, 284, 319, 333, 389, 391, 398, 412, 421, 428, 444, 469, 482, 496, 555, 649, 666, 694, 777, 811, 818, 824, 839, 842, 881, 888, 893, 913, 931 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS No number with a 0 in it (A011540) can be in this sequence. If a number is in this sequence, then so is its reversal of digits (A004086) and other permutations of its digits. - Alonso del Arte, Feb 20 2014 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA There are between 9^(k-6) and 9^k k-digit members of this sequence, so a(n) >> n^1.04 and in particular this sequence has density 0. - Charles R Greathouse IV, Feb 21 2014 EXAMPLE 3*9*1 = 27 = 3^3, thus 391 is a member of this sequence. 3*9*8 = 216 = 6^3, thus 398 is a member of this sequence. 4*2*8 = 64 = 4^3, thus 428 is a member of this sequence. MATHEMATICA pdcQ[n_]:=Module[{idn=IntegerDigits[n]}, FreeQ[idn, 0]&&IntegerQ[ Surd[ Times@@idn, 3]]]; Select[Range[1000], pdcQ] (* Harvey P. Dale, Aug 25 2017 *) PROG (Python) def DigitProd(x): ..total = 1 ..for i in str(x): ....total *= int(i) ..return total def Cube(x): ..for n in range(1, 10**3): ....if DigitProd(x) == n**3: ......return True ....if DigitProd(x) < n**3: ......return False ..return False x = 1 while x < 1000: ..if Cube(x): ....print(x) ..x += 1 (PARI) s=[]; for(n=1, 1000, t=eval(Vec(Str(n))); d=prod(i=1, #t, t[i]); if(d>0 && ispower(d, 3), s=concat(s, n))); s \\ Colin Barker, Feb 17 2014 CROSSREFS Cf. A007954, A050626. Sequence in context: A291663 A306277 A067469 * A284324 A205856 A318079 Adjacent sequences:  A237764 A237765 A237766 * A237768 A237769 A237770 KEYWORD nonn,base AUTHOR Derek Orr, Feb 12 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 15 08:46 EDT 2022. Contains 356135 sequences. (Running on oeis4.)