This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A241213 a(n) is built digit-by-digit (see comments for details). 1
 1, 2, 3, 4, 5, 10, 11, 12, 13, 14, 15, 20, 21, 22, 23, 24, 25, 30, 31, 32, 33, 34, 35, 40, 41, 42, 43, 44, 45, 100, 101, 102, 103, 104, 105, 110, 111, 112, 113, 114, 115, 120, 121, 122, 123, 124, 125, 130, 131, 132, 133, 134, 135, 140, 141, 142, 143, 144, 145 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) is built digit-by-digit as a_i ... a_3 a_2 a_1. Note that in this case, the definition of digit is a nonnegative integer. If i > 3, number digits of a_i may be greater than 1. Successively, we have: a_1 = n mod 6; a_2 = ((n - a_1)/primorial(2)) mod prime(2+1); a_3 = ((n - a_1 - a_2*primorial(2))/primorial(3)) mod prime(3+1); ... a_i = ((n - a_1 - a_2*primorial(2)-...-a_(i-1)*primorial(i-1))/primorial(i)) mod prime(i+1). So that finally, n = a_1 + a_2*primorial(2) + ... + a_i*primorial(i). LINKS Lear Young, Table of n, a(n) for n = 1..100000 EXAMPLE a(2287) = 10611. 10611 is built digit-by-digit as a_4 a_3 a_2 a_1 = 10 6 1 1. And a_1+a_2*primorial(2)+a_3*primorial(3)+a_4*primorial(4) = 1 + 1*6 + 6*30 + 10*210 = 2287. (Definition of digit is nonnegative integer. See comments for how to get a_1, a_2, a_3, a_4.) PROG (Sage) Pr = Primes() c = oeis(2110)[:10] def bjz(a):     d = len(str(a)) + 1     b  = [0] * (d)     b[0] = a % 6     s = 0     for x in range(1, d):         if x > 1:             s += c[x] * b[x-1]         b[x] = ((a - b[0] - s) / c[x+1] ) % Pr.unrank(x+1)     return int(''.join(map(str, b[::-1]))) [ bjz(x)  for x in range(1, 101)] # Lear Young, Apr 17 2014 CROSSREFS Sequence in context: A266117 A037473 A007092 * A047596 A199502 A089964 Adjacent sequences:  A241210 A241211 A241212 * A241214 A241215 A241216 KEYWORD nonn,base AUTHOR Lear Young, Apr 17 2014 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 June 20 16:26 EDT 2019. Contains 324234 sequences. (Running on oeis4.)