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 A083888 Number of divisors of n with largest digit = 1 (base 10). 11
 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,10 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A000005(n) - A083889(n) - A083890(n) - A083891(n) - A083892(n) - A083893(n) - A083894(n) - A083895(n) - A083896(n). Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{k>=1} 1/A007088(k) = 1.23840561530559480971... . - Amiram Eldar, Jan 04 2024 EXAMPLE n=110, 4 of the divisors of 110 {1,2,5,10,11,22,55,110} have largest digit =1: {1,10,11,110}, therefore a(110)=4. MAPLE f:= proc(n) nops(select(t -> max(convert(t, base, 10))=d, numtheory:-divisors(n))) end proc: d:= 1: map(f, [\$1..200]); # Robert Israel, Oct 06 2019 MATHEMATICA With[{k = 1}, Array[DivisorSum[#, 1 &, And[#[[k]] > 0, Total@ #[[k + 1 ;; 9]] == 0] &@ DigitCount[#] &] &, 105]] (* Michael De Vlieger, Oct 06 2019 *) PROG (Magma) [#[d:d in Divisors(n) | Max(Intseq(d)) eq 1]: n in [1..110]]; // Marius A. Burtea, Oct 06 2019 CROSSREFS Cf. A054055, A000005, A007088, A083889, A083890, A083891, A083892, A083893, A083894, A083895, A083896. Sequence in context: A370958 A335208 A165735 * A102681 A274013 A172086 Adjacent sequences: A083885 A083886 A083887 * A083889 A083890 A083891 KEYWORD nonn,base AUTHOR Reinhard Zumkeller, May 08 2003 STATUS approved

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Last modified September 8 04:40 EDT 2024. Contains 375751 sequences. (Running on oeis4.)