This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A268357 Highest power of 11 dividing n. 4
 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 121, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,11 COMMENTS The generalized binomial coefficients produced by this sequence provide an analog to Kummer's Theorem using arithmetic in base 11. This first index where this differs from A109014 is 121; a(121) = 121 and A109014(121) = 11. LINKS Tyler Ball, Tom Edgar, and Daniel Juda, Dominance Orders, Generalized Binomial Coefficients, and Kummer's Theorem, Mathematics Magazine, Vol. 87, No. 2, April 2014, pp. 135-143. Tom Edgar and Michael Z. Spivey, Multiplicative functions, generalized binomial coefficients, and generalized Catalan numbers, Journal of Integer Sequences, Vol. 19 (2016), Article 16.1.6. FORMULA a(n) = 11^valuation(n,11). Completely multiplicative with a(11) = 11, a(p) = 1 for prime p and p<>11. - Andrew Howroyd, Jul 20 2018 From Peter Bala, Feb 21 2019: (Start) a(n) = gcd(n,11^n). O.g.f.: x/(1 - x) + 10*Sum_{n >= 1} 11^(n-1)*x^(11^n)/ (1 - x^(11^n)). (End). EXAMPLE Since 22 = 11 * 2, a(22) = 11. Likewise, since 11 does not divide 21, a(21) = 1. MATHEMATICA Table[11^IntegerExponent[n, 11], {n, 130}] (* Bruno Berselli, Feb 03 2016 *) PROG (Sage) [11^valuation(i, 11) for i in [1..130]] (MAGMA) [11^Valuation(n, 11): n in [1..130]]; // Vincenzo Librandi, Feb 03 2016 CROSSREFS Cf. A006519, A038500, A234957, A234959, A109014, A268354, A060904. Sequence in context: A118135 A318671 A109014 * A321804 A321800 A130837 Adjacent sequences:  A268354 A268355 A268356 * A268358 A268359 A268360 KEYWORD nonn,easy,mult,changed AUTHOR Tom Edgar, Feb 02 2016 STATUS approved

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

Last modified April 20 09:59 EDT 2019. Contains 322309 sequences. (Running on oeis4.)