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 A087997 a(n) is the least number with n palindromic divisors. 12
 1, 2, 4, 6, 12, 24, 72, 66, 484, 132, 616, 264, 2112, 792, 1848, 2772, 7326, 8712, 5544, 13332, 14652, 24024, 36036, 26664, 87912, 102564, 72072, 79992, 186648, 205128, 360360, 279972, 264264, 666666, 1213212, 879912, 559944, 888888, 792792 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Donovan Johnson, Table of n, a(n) for n = 1..150 FORMULA a(n)=Min{x; A087990[x]=n} EXAMPLE n=24: a(24)=26664 has 32 divisors of which 24 are palindromic numbers: {1, 2, 3, 4, 6, 8, 11, 22, 33, 44, 66, 88, 101, 202, 303, 404, 606, 808, 1111, 2222, 3333, 4444, 6666, 8888}. Some solutions are palindromic (like 2112), some are not (like 132). MATHEMATICA t = Table[Count[Divisors[k], _?(Reverse[x = IntegerDigits[#]] == x &)], {k, 2, 15*10^5, 2}]; Join[{1}, Table[i = 1; While[t[[i]] != k, i++]; 2 i, {k, 2, 39}]] (* Jayanta Basu, Aug 12 2013 *) Module[{pds=Table[{n, Count[Divisors[n], _?PalindromeQ]}, {n, 1214000}]}, Table[ SelectFirst[pds, #[[2]]==k&], {k, 39}]][[All, 1]] (* Harvey P. Dale, Dec 17 2021 *) CROSSREFS Cf. A087990. Sequence in context: A337993 A093036 A340548 * A355699 A340638 A177905 Adjacent sequences: A087994 A087995 A087996 * A087998 A087999 A088000 KEYWORD base,nonn AUTHOR Labos Elemer, Oct 13 2003 EXTENSIONS More terms from Ray Chandler, Oct 17 2003 STATUS approved

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Last modified February 5 23:07 EST 2023. Contains 360091 sequences. (Running on oeis4.)