A354577 Variant of A253028 using only even numbers: a mirror symmetric array of even numbers where the n-th term is equal to the number of terms in the n-th row of the array.

2, 4, 6, 2, 4, 8, 10, 6, 2, 4, 8, 12, 14, 16, 18, 10, 12, 20, 22, 14, 6, 2, 4, 8, 16, 24, 26, 18, 10, 6, 2, 4, 8, 12, 20, 28, 30, 22, 14, 16, 24, 32, 34, 36, 38, 26, 28, 40, 42, 30, 18, 10, 12, 20, 32, 44, 46, 34, 22, 14, 6, 2, 4, 8, 16, 24, 36, 48, 50, 38, 26

Offset

1,1

Comments

See the examples in A253028 for a detailed illustration of how the array is constructed.

Links

Table of n, a(n) for n=1..71.

Rémy Sigrist, PARI program

Example

1.........................2,4
2.......................6,2,4,8
3....................10,6,2,4,8,12
4........................14,16
5.....................18,10,12,20
6.................22,14,6,2,4,8,16,24
7..............26,18,10,6,2,4,8,12,20,28
8..................30,22,14,16,24,32
9........................34,36
10....................38,26,28,40
11..............42,30,18,10,12,20,32,44
12..........46,34,22,14,6,2,4,8,16,24,36,48
13.......50,38,26,18,10,6,2,4,8,12,20,28,40,52

Prog

(PARI) See Links section.

Crossrefs

Cf. A253028, A354576.

Sequence in context: A161489 A050975 A053446 * A133903 A278263 A236188

Adjacent sequences: A354574 A354575 A354576 * A354578 A354579 A354580

Keyword

nonn,tabf

Author

Felix Fröhlich, May 30 2022

Status

approved