A341706 Row 2 of semigroup multiplication table shown in A341317 and A341318.

0, 2, 7, 8, 16, 17, 18, 29, 30, 31, 32, 46, 47, 48, 49, 50, 67, 68, 69, 70, 71, 72, 92, 93, 94, 95, 96, 97, 98, 121, 122, 123, 124, 125, 126, 127, 128, 154, 155, 156, 157, 158, 159, 160, 161, 162, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 232, 233, 234

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..10000

Maple

t:= n-> n*(n-1)/2:
f:= n-> ceil((sqrt(1+8*n)-1)/2):
g:= n-> (x-> [x, n-t(x)][])(f(n)):
a:= n-> (h-> t(h[1]*h[3])+h[2]*h[4])(map(g, [n, 2])):
seq(a(n), n=0..60);  # Alois P. Heinz, Feb 17 2021

Crossrefs

Cf. A341317, A341318.

Sequence in context: A080572 A263602 A162664 * A032689 A331489 A300476

Adjacent sequences: A341703 A341704 A341705 * A341707 A341708 A341709

Keyword

nonn

Author

N. J. A. Sloane, Feb 17 2021

Extensions

More terms from Alois P. Heinz, Feb 17 2021

Status

approved