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A084054 5*n digit-reversed mod 5. 6
1, 1, 2, 2, 3, 3, 4, 4, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

COMMENTS

The pattern of increasing frequency of repetition of digits is clear.

LINKS

Table of n, a(n) for n=2..106.

FORMULA

Contribution from Enrique Pérez Herrero, Jun 14 2010: (Start)

a(n)=mod(floor(5*n/10^(floor(log_10(5*n)))),5), this formula comes from the modulus 5 of the first digit of 5*n.

a(10^n)=1

(End)

EXAMPLE

a(61) =3 as, 61*5 = 305,digit reversed = 503 ==3 (mod 5)

MATHEMATICA

Contribution from Enrique Pérez Herrero, Jun 14 2010: (Start)

A084054[n_Integer]:=Mod[FromDigits[Reverse[IntegerDigits[5*n]]], 5];

(* Alternative formula *)

A084054[n_Integer]:=Mod[Floor[5*n/10^Floor[Log[10, 5*n]]], 5] (End)

CROSSREFS

Cf. A084052, A084053, A084055, A084339, A084340, A084341.

Sequence in context: A117171 A325356 A304706 * A106747 A083447 A252489

Adjacent sequences:  A084051 A084052 A084053 * A084055 A084056 A084057

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 26 2003

EXTENSIONS

More terms from Ray Chandler, May 27 2003

STATUS

approved

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Last modified March 28 05:38 EDT 2020. Contains 333073 sequences. (Running on oeis4.)