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 A066613 Product of the nonzero digits = number of divisors. 2
 1, 2, 14, 22, 24, 32, 42, 116, 122, 126, 141, 202, 211, 221, 222, 260, 280, 340, 402, 411, 440, 512, 620, 840, 1021, 1041, 1062, 1114, 1118, 1128, 1132, 1141, 1144, 1201, 1202, 1206, 1218, 1222, 1242, 1250, 1314, 1332, 1340, 1380, 1401, 1411, 1602, 1611 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Giovanni Resta, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harry J. Smith) EXAMPLE 24 is a term as there are 8 divisors of 24 = 2*4. MATHEMATICA f[n_] := Block[ {a = Sort[ IntegerDigits[n]] }, While[ First[a] == 0, a = Drop[a, 1]]; Return[ Apply[ Times, a]]]; Select[ Range[10^4], f[ # ] == Length[ Divisors[ # ]] & ] pndQ[n_]:=Times@@Select[IntegerDigits[n], #!=0&]==DivisorSigma[0, n]; Select[Range[2000], pndQ] (* Harvey P. Dale, Oct 25 2016 *) PROG (PARI) ProdNzD(x)= { local(d, p=1); while (x>9, d=x%10; if (d, p*=d); x\=10); return(p*x) } { n=0; for (m=1, 10^10, if (ProdNzD(m) == numdiv(m), write("b066613.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Mar 12 2010 CROSSREFS Cf. A074312. Sequence in context: A355709 A335071 A073143 * A074312 A061426 A190045 Adjacent sequences: A066610 A066611 A066612 * A066614 A066615 A066616 KEYWORD nonn,base AUTHOR Amarnath Murthy, Dec 24 2001 EXTENSIONS Corrected and extended by Jason Earls and Robert G. Wilson v, Dec 26 2001 STATUS approved

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Last modified September 18 14:15 EDT 2024. Contains 376000 sequences. (Running on oeis4.)