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 A367250 a(n) is the number of n-digit numbers whose difference between the largest and smallest digits is equal to 9. 7
 0, 1, 35, 703, 11231, 158311, 2062655, 25466743, 302423471, 3487593511, 39314599775, 435241463383, 4748453693711, 51186327429511, 546278900354495, 5781325731101623, 60750456603203951, 634502309615150311, 6592506388026870815, 68188442304165981463, 702543059232886986191 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(n) is the number of n-digit numbers in A366966. LINKS Table of n, a(n) for n=1..21. Index entries for linear recurrences with constant coefficients, signature (27,-242,720). FORMULA a(n) = 9*10^(n-1) - 17*9^(n-1) + 8^n. a(n) = 27*a(n-1) - 242*a(n-2) + 720*a(n-3) for n > 3. O.g.f.: x^2*(1 + 8*x)/((1 - 8*x)*(1 - 9*x)*(1 - 10*x)). E.g.f.: (81*exp(10*x) - 170*exp(9*x) + 90*exp(8*x) - 1)/90. MATHEMATICA LinearRecurrence[{27, -242, 720}, {0, 1, 35}, 21] CROSSREFS Cf. A366966. Cf. A001018, A001019, A011557. Cf. A367243, A367244, A367245, A367246, A367247, A367248, A367249. Sequence in context: A175774 A112504 A140405 * A278361 A145603 A326865 Adjacent sequences: A367247 A367248 A367249 * A367251 A367252 A367253 KEYWORD nonn,base,easy AUTHOR Stefano Spezia, Nov 11 2023 STATUS approved

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Last modified June 24 18:22 EDT 2024. Contains 373687 sequences. (Running on oeis4.)