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A071876 Decimal expansion of the ninth (of 10) decimal selvage number; the n-th digit of a decimal selvage number, x, is equal to the tenths digit of n*x. 9
7, 5, 2, 0, 7, 5, 2, 0, 7, 5, 2, 0, 7, 5, 2, 0, 7, 5, 2, 0, 7, 5, 2, 0, 8, 5, 3, 0, 8, 5, 3, 0, 8, 5, 3, 0, 8, 5, 3, 0, 8, 5, 3, 0, 8, 5, 3, 0, 8, 6, 3, 1, 8, 6, 3, 1, 8, 6, 3, 1, 8, 6, 3, 1, 8, 6, 3, 1, 8, 6, 3, 1, 9, 6, 4, 1, 9, 6, 4, 1, 9, 6, 4, 1, 9, 6, 4, 1, 9, 6, 4, 1, 9, 6, 4, 1, 9, 7, 4, 2 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
In other words, this constant satisfies x = Sum_{n>=0} ( floor(10*n*x) (mod 10) ) / 10^n.
The ninth selvage number is equal to the complement of the second selvage number (A071790): s_9 = 1 - s_2.
LINKS
FORMULA
a(n) = floor[10*(n*x)] (Mod 10), where x = sum{k=1..inf} a(k)/10^k.
a(n) = 9 - A071790(n).
EXAMPLE
x=0.75207520752075207520752085308530853085308530853086...
a(7) = 2 since floor(10*(7*x)) (Mod 10) = 2.
The multiples of this constant x begin:
1*x = 0.7520752075207520752075208530853085308531...
2*x = 1.504150415041504150415041706170617061706...
3*x = 2.256225622562256225622562559255925592559...
4*x = 3.008300830083008300830083412341234123412...
5*x = 3.760376037603760376037604265426542654265...
6*x = 4.512451245124512451245125118511851185119...
7*x = 5.264526452645264526452645971597159715972...
8*x = 6.016601660166016601660166824682468246825...
9*x = 6.768676867686768676867687677767776777678...
10*x = 7.520752075207520752075208530853085308531...
11*x = 8.272827282728272827282729383938393839384...
12*x = 9.024902490249024902490250237023702370237...
wherein the tenths place of n*x yields the n-th digit of x.
MATHEMATICA
Clear[a]; a[1] = 7; a[2] = 5; a[n0=3] = 2; a[_] = 0; digits = 10^(n0-1); Do[a[n] = Mod[Floor[10*n*Sum[a[k]/10^k, {k, 1, n}]], 10], {n, n0+1, digits}]; Table[a[n], {n, 1, digits}] (* Jean-François Alcover, May 12 2015 *)
CROSSREFS
Sequence in context: A272169 A084911 A073742 * A306538 A191503 A318172
KEYWORD
cons,easy,nonn,base
AUTHOR
Paul D. Hanna, Jun 10 2002
STATUS
approved

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Last modified May 21 00:58 EDT 2024. Contains 372720 sequences. (Running on oeis4.)