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A169933

a(n) = 2+n in the arithmetic defined in A169918.

0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78

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OFFSET

0,2

COMMENTS

Equivalently, apply to the last (decimal) digit of n the operation d->((d*2) mod 10), i.e., multiply the last digit by 2 and take this modulo 10; keep all other digits the same. - M. F. Hasler, Mar 25 2015

LINKS

Table of n, a(n) for n=0..74.

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,0,1,-1).

FORMULA

For n > 9, a(n) = a(n-10) + 10. For n < 10, a(n) = (2*n mod 10). - M. F. Hasler, Mar 25 2015

From Chai Wah Wu, Feb 02 2023: (Start)

a(n) = a(n-1) + a(n-10) - a(n-11) for n > 10.

G.f.: 2*x*(x^9 + x^8 + x^7 + x^6 + x^5 - 4*x^4 + x^3 + x^2 + x + 1)/(x^11 - x^10 - x + 1). (End)

PROG

(PARI) A169933(n)=n-n%10+(n*2)%10 \\ M. F. Hasler, Mar 25 2015

(Magma) [n - n mod 10 + 2*n mod 10: n in [0..70]]; // Vincenzo Librandi, Mar 26 2015

CROSSREFS