The On-Line Encyclopedia of Integer Sequences (OEIS)

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

Revision History for A281968

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing all changes.

A281968

Number of sets of exactly n positive integers <= n+5 having a square element sum.
(history; published version)

#6 by Alois P. Heinz at Fri Feb 03 19:58:19 EST 2017

STATUS

editing

approved

#5 by Alois P. Heinz at Fri Feb 03 19:58:15 EST 2017

EXAMPLE

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

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

a(4) = 14: {1,2,4,9}, {1,2,5,8}, {1,2,6,7}, {1,3,4,8}, {1,3,5,7}, {1,4,5,6}, {1,7,8,9}, {2,3,4,7}, {2,3,5,6}, {2,6,8,9}, {3,5,8,9}, {3,6,7,9}, {4,5,7,9}, {4,6,7,8}.

STATUS

approved

editing

#4 by Alois P. Heinz at Fri Feb 03 19:20:27 EST 2017

STATUS

editing

approved

#3 by Alois P. Heinz at Fri Feb 03 19:20:23 EST 2017

LINKS

Alois P. Heinz, <a href="/A281968/b281968.txt">Table of n, a(n) for n = 0..1000</a>

#2 by Alois P. Heinz at Fri Feb 03 16:40:03 EST 2017

NAME

allocated for Alois P. Heinz

Number of sets of exactly n positive integers <= n+5 having a square element sum.

DATA

1, 2, 4, 8, 14, 24, 39, 60, 86, 121, 171, 228, 294, 387, 499, 614, 762, 953, 1152, 1362, 1654, 1979, 2280, 2678, 3167, 3628, 4117, 4798, 5498, 6109, 6968, 7967, 8824, 9793, 11127, 12382, 13462, 15088, 16845, 18230, 19981, 22294, 24272, 26047, 28849, 31616

OFFSET

0,2

FORMULA

a(n) = A281871(n+5,n).

CROSSREFS

A diagonal of A281871.

KEYWORD

allocated

nonn

AUTHOR

Alois P. Heinz, Feb 03 2017

STATUS

approved

editing

#1 by Alois P. Heinz at Fri Feb 03 16:20:31 EST 2017

NAME

allocated for Alois P. Heinz

KEYWORD

allocated

STATUS

approved