id:A074927 - OEIS Search Results

Search: id:A074927

Displaying 1-1 of 1 results found.

page 1

a(n) such that p(n)*p(n+1)+a(n) is a minimal square.

+0
5

3, 1, 1, 4, 1, 4, 1, 4, 9, 1, 9, 4, 1, 4, 9, 9, 1, 9, 4, 1, 9, 4, 9, 16, 4, 1, 4, 1, 4, 49, 4, 9, 1, 25, 1, 9, 9, 4, 9, 9, 1, 25, 1, 4, 1, 36, 36, 4, 1, 4, 9, 1, 25, 9, 9, 9, 1, 9, 4, 1, 25, 49, 4, 1, 4, 49, 9, 25, 1, 4, 9, 16, 9, 9, 4, 9, 16, 4, 16, 25, 1, 25, 1, 9, 4, 9, 16, 4, 1, 4, 36, 16, 4 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`When a(n)=1, p(n) and p(n+1) are twin primes.` `a(n+1) = A072681(A024675(n)). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 04 2009]`
	FORMULA	`For n>1: a(n) = ((p(n+1)-p(n))/2)^2. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 22 2002`
	EXAMPLE	`a(154) = 100 because p(154)*p(155) + 100 = 804509 = 897^2.`
	CROSSREFS	`Sequence in context: A104610 A138684 A132442 this_sequence A139605 A098712 A023579` `Adjacent sequences: A074924 A074925 A074926 this_sequence A074928 A074929 A074930`
	KEYWORD	`nonn`
	AUTHOR	`Zak Seidov (zakseidov(AT)yahoo.com), Oct 02 2002`

page 1

Search completed in 0.002 seconds

Last modified December 15 00:47 EST 2009. Contains 170825 sequences.

AT&T Labs Research