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A136275
Similar to A137284, but considering Sum{ k = 1,2,3,... } 5^(-nk).
1
1, 2, 3, 5, 8, 12, 18, 26, 38, 55, 79, 114, 164, 235, 337, 483, 692, 991, 1418, 2029, 2903, 4154, 5944, 8504, 12167, 17408, 24906, 35633, 50980, 72936, 104348, 149289, 213585, 305572, 437175, 625457, 894827, 1280209, 1831566, 2620379, 3748915
OFFSET
0,2
LINKS
FORMULA
a(n) = ceiling( a(n-1)*log_5(10) ). - Max Alekseyev, May 14 2009
EXAMPLE
Start from 0;
0 + 5^(-1) = 0.2;
0.2 + 5^(-2) = 0.24 (first digit "2" is equal to the previous number's digit after the decimal point);
0.24 + 5^(-3) = 0.248 (first digits "24" are equal to the previous number's digits after the decimal point);
0.248 + 5^(-5) = 0.24832 (first digits "248" are equal to the previous number's digits after the decimal point);
etc.
MATHEMATICA
Join[{1}, a=1; a=Table[a=Ceiling[a Log[5, 10]], {n, 40}]] (* Vincenzo Librandi, Jul 05 2019 *)
PROG
(Magma) [n eq 1 select 1 else Ceiling(Self(n-1)*Log(5, 10)): n in [1..50]]; // Vincenzo Librandi, Jul 05 2019
CROSSREFS
Sequence in context: A328085 A001524 A280278 * A344002 A328170 A078408
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
Extended by Max Alekseyev, May 14 2009
STATUS
approved