A057105 - OEIS

This site is supported by donations to The OEIS Foundation.

A057105

Triangle of numbers (when unsigned) related to congruum problem: T(n,k)=k^2+2nk-n^2 with n>k>0 and starting at T(2,1)=1.

1, -2, 7, -7, 4, 17, -14, -1, 14, 31, -23, -8, 9, 28, 49, -34, -17, 2, 23, 46, 71, -47, -28, -7, 16, 41, 68, 97, -62, -41, -18, 7, 34, 63, 94, 127, -79, -56, -31, -4, 25, 56, 89, 124, 161, -98, -73, -46, -17, 14, 47, 82, 119, 158, 199, -119, -92, -63, -32, 1, 36, 73, 112, 153, 196, 241, -142, -113, -82, -49, -14, 23, 62, 103 (list; table; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Signed values are only relevant for the explicit formula.`
	LINKS	`Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.`
	FORMULA	`Unsigned: a(n) =sqrt(A055096(n)^2-A057103(n)) =sqrt(A056203(n)^2-2*A057103(n)).`
	EXAMPLE	`a(1)=T(2,1)=1^2+221-2^2=1`
	CROSSREFS	`Cf. A057102. The congruum problem is about finding solutions for h (A057103) where there are integers x (A055096), y (A057105 unsigned) and z (A056203) such that h=x^2-y^2=z^2-x^2.` `Sequence in context: A164767 A188636 A021977 * A016536 A189960 A063503` `Adjacent sequences: A057102 A057103 A057104 * A057106 A057107 A057108`
	KEYWORD	`sign,tabl`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Aug 02 2000`

Content is available under The OEIS End-User License Agreement .

Last modified February 17 08:21 EST 2012. Contains 205998 sequences.