|
Search: id:A078667
|
|
|
| A078667 |
|
Integers that occur more than once as as the difference [p_n]^2 - [p_(n-1)]^2 of the squares of two consecutive primes. |
|
+0
8
|
|
| 72, 120, 168, 312, 408, 552, 600, 768, 792, 912, 1032, 1848, 1848, 2472, 3048, 3192, 3288, 3528, 3720, 4008, 4920, 4920, 4920, 5160, 5208, 5808, 5928, 6072, 6480, 6792, 6840, 6888, 6888, 7080, 7152, 7248, 7512, 7728, 7800, 8520, 8760, 9072, 11400
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
120=31^2-29^2=17^2-13^2
|
|
PROGRAM
|
(PARI) pv(v)=vecsort(vecextract(v, concat("1..", vc-1))) op=2; v=vector(5000); vc=1; forprime (p=3, 5000, v[vc]=p^2-op^2; vc++; op=p) v=pv(v) for (i=2, length(v), if (v[i]==v[i-1], print1(v[i]", ")))
(PARI) pv(v)=vecsort(vecextract(v, concat("1..", vc-1))) op=2; v=vector(5000); vc=1; forprime (p=3, 5000, v[vc]= p^2-op^2; vc++; op=p) v=pv(v) for (i=2, length(v), if (v[i]==v[i-1], print1(v[i]", ")))
|
|
CROSSREFS
|
Cf. A090783, A090784, A090785, A091878.
Adjacent sequences: A078664 A078665 A078666 this_sequence A078668 A078669 A078670
Sequence in context: A052486 A114128 A143610 this_sequence A090784 A060661 A050495
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Jon Perry (perry(AT)globalnet.co.uk), Dec 15 2002
|
|
|
Search completed in 0.002 seconds
|
