A243590 Numbers returned when each digit of n is replaced by the sum modulo 10 of the digits to its (wrapped) left and (wrapped) right.

2, 4, 6, 8, 0, 2, 4, 6, 8, 2, 22, 42, 62, 82, 2, 22, 42, 62, 82, 4, 24, 44, 64, 84, 4, 24, 44, 64, 84, 6, 26, 46, 66, 86, 6, 26, 46, 66, 86, 8, 28, 48, 68, 88, 8, 28, 48, 68, 88, 0, 20, 40, 60, 80, 0, 20, 40, 60, 80, 2, 22, 42, 62, 82, 2, 22, 42, 62, 82, 4, 24

Offset

1,1

Comments

Numbers returned by the following function: take the t digits of n, d(1)..d(t), and replace each with the sum d(i) = (d(i-1) + d(i+1)) mod 10, where (i-1 = 0) maps to t and (i+1 > t) maps to 1.

Links

Anthony Sand, Table of n, a(n) for n = 1..1000

Formula

for digits d(1)..d(t), d(i) = (d(i-1) + d(i+1)) mod 10, where (i-1 = 0) -> t, (i+1 > t) -> 1.

Example

For 1, the function returns (1 + 1) mod 10 = 2.
For 5, the function returns (5 + 5) mod 10 = 0.
For 125, the initial digits are (1,2,5).
d(1) <- (d(3) + d(2)) mod 10 = (5 + 2) mod 10 = 7; d(2) <- (d(1) + d(3)) mod 10 = (1 + 5) mod 10 = 6; d(3) <- (d(2) + d(1)) mod 10 = (2 + 1) mod 10 = 3.
The function returns (7,6,3) = 763.

Crossrefs

Cf. A055120, A035327.

Sequence in context: A275693 A135033 A317647 * A169933 A113603 A004520

Adjacent sequences: A243587 A243588 A243589 * A243591 A243592 A243593

Keyword

nonn,base

Author

Anthony Sand, Jun 07 2014

Status

approved