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A056221 Image of primes (A000040) under "little Hankel" transform that sends [c_0, c_1, ...] to [d_0, d_1, ...] where d_n = c_n^2 - c_{n+1}*c_{n-1}. 4
-1, 4, -6, 30, -18, 42, -30, -22, 128, -112, 98, 90, -78, -70, 36, 248, -232, 158, 150, -280, 182, -142, -130, 420, 210, -198, 222, -210, -1074, 1326, -238, 560, -1092, 1212, -592, 36, 350, -310, 36, 728, -1428, 1548, -378, 402, -1966, 144, 1832, 462, -450, -442 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..50.

L. Panaitopol, On the sequence p(n)^2=p(n-1)*p(n+1), J. Inequal. Pure Appl. Math., Volume 3, Issue 4, Article 53, 2002.

FORMULA

a(n) = determinant of matrix

| prime(n+1) prime(n)|

| prime(n+2) prime(n+1)|. - Zak Seidov, Jul 23 2008, indices corrected by Gary Detlefs, Dec 09 2011

MAPLE

A056221 := proc(n)

        ithprime(n+1)^2-ithprime(n)*ithprime(n+2) ;

end proc:

seq(A056221(n), n=1..10) ; # R. J. Mathar, Dec 10 2011

CROSSREFS

Sequence in context: A093815 A142859 A259087 * A046849 A090530 A154667

Adjacent sequences:  A056218 A056219 A056220 * A056222 A056223 A056224

KEYWORD

sign

AUTHOR

N. J. A. Sloane, Aug 06 2000

STATUS

approved

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Last modified November 20 12:30 EST 2017. Contains 294971 sequences.