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

Author

Felix Fröhlich, May 30 2022

Keywords

• nonn
• tabf

Comments

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

Examples

			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
		

Links

• Rémy Sigrist, PARI program

Crossrefs

Cf. A253028, A354576.

Programs

PARI

See Links section.