A077552 Consider the following triangle in which the n-th row contains n distinct numbers whose product is the smallest and has the least possible number of divisors. 1 is a member of only the first row. Sequence contains the final term of the rows (the leading diagonal).

1, 3, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648

Offset

0,2

Comments

N points are chosen on a circle to get n arcs of different lengths. Then a(n-1) counts - Anton Zakharov, Dec 14 2016

Links

Table of n, a(n) for n=0..30.

Formula

For n>2, a(n)=2^n. - Ray Chandler, Aug 21 2003

Row sums of triangle A132309. - Gary W. Adamson, Aug 18 2007

Example

Triangle begins
1
2 3
2 4 8
2 4 8 16
2 4 8 16 32

Mathematica

Table[2^(n + 1) - Boole[n < 2], {n, 0, 30}] (* Michael De Vlieger, Mar 15 2017 *)

Crossrefs

Cf. A132309.

Sequence in context: A005103 A001978 A173283 * A171497 A024623 A337118

Adjacent sequences: A077549 A077550 A077551 * A077553 A077554 A077555

Keyword

nonn

Author

Amarnath Murthy, Nov 10 2002

Extensions

Corrected and extended by Ray Chandler, Aug 21 2003

Status

approved