login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A281966 Number of sets of exactly n positive integers <= n+3 having a square element sum. 2
1, 2, 2, 3, 5, 6, 7, 10, 13, 14, 16, 21, 25, 24, 31, 37, 37, 40, 50, 55, 51, 64, 74, 69, 77, 92, 95, 89, 111, 122, 110, 127, 146, 145, 139, 171, 181, 161, 191, 213, 202, 203, 243, 250, 222, 270, 292, 264, 285, 328, 326, 296, 362, 381, 335, 383, 425, 407, 388 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

FORMULA

a(n) = A281871(n+3,n).

EXAMPLE

a(3) = 3: {1,2,6}, {1,3,5}, {2,3,4}.

a(4) = 5: {1,2,6,7}, {1,3,5,7}, {1,4,5,6}, {2,3,4,7}, {2,3,5,6}.

a(5) = 6: {1,2,3,4,6}, {1,3,6,7,8}, {1,4,5,7,8}, {2,3,5,7,8}, {2,4,5,6,8}, {3,4,5,6,7}.

CROSSREFS

A diagonal of A281871.

Sequence in context: A218933 A266746 A096981 * A276431 A308272 A035541

Adjacent sequences: A281963 A281964 A281965 * A281967 A281968 A281969

KEYWORD

nonn,look

AUTHOR

Alois P. Heinz, Feb 03 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 14:39 EDT 2023. Contains 361599 sequences. (Running on oeis4.)