login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130111 Rearrangement of natural numbers such that each five terms sum up to a perfect square. 3
1, 2, 3, 4, 6, 5, 7, 8, 9, 20, 10, 11, 12, 13, 18, 14, 15, 16, 17, 19, 21, 22, 23, 24, 31, 25, 26, 27, 28, 38, 29, 30, 32, 33, 45, 34, 35, 36, 37, 54, 39, 40, 41, 42, 63, 43, 44, 46, 47, 76, 48, 49, 50, 51, 58, 52, 53, 55, 56, 73, 57, 59, 60, 61, 87, 62, 64, 65, 66, 67, 68, 69 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..72.

EXAMPLE

1+2+3+4+6=16, 5+7+8+9+20=49, 10+11+12+13+18=64, 14+15+16+17+19=81.

MATHEMATICA

s={}; ra=Range[1000]; Do[su=ra[[1]]+ra[[2]]+ra[[3]]+ra[[4]]; c=5; While[ !IntegerQ[Sqrt[su+ra[[c]]]], c++ ]; rac=ra[[c]]; s=Join[s, {ra[[1]], ra[[2]], ra[[3]], ra[[4]], rac}]; ra=Complement[ra, {ra[[1]], ra[[2]], ra[[3]], ra[[4]], rac}], {50}]; s

CROSSREFS

Cf. A130108, A130109, A130110.

Sequence in context: A057508 A057164 A085175 * A104182 A267106 A275119

Adjacent sequences:  A130108 A130109 A130110 * A130112 A130113 A130114

KEYWORD

nonn

AUTHOR

Zak Seidov, May 08 2007

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 18 22:11 EDT 2019. Contains 321305 sequences. (Running on oeis4.)