

A092242


Numbers that are congruent to {5, 7} mod 12.


2



5, 7, 17, 19, 29, 31, 41, 43, 53, 55, 65, 67, 77, 79, 89, 91, 101, 103, 113, 115, 125, 127, 137, 139, 149, 151, 161, 163, 173, 175, 185, 187, 197, 199, 209, 211, 221, 223, 233, 235, 245, 247, 257, 259, 269, 271, 281, 283, 293, 295, 305, 307, 317, 319, 329, 331
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


REFERENCES

L. B. W. Jolley, "Summation of Series", Dover Publications, 1961, p. 64.


LINKS

Table of n, a(n) for n=1..56.
Index entries for linear recurrences with constant coefficients, signature (1,1,1).


FORMULA

1/5^2 + 1/7^2 + 1/17^2 + 1/19^2 + 1/29^2 + 1/31^2...= (Pi^2*(2  sqrt(3))/36 = 0.073459792... [Jolley]  Gary W. Adamson, Dec 20 2006
a(n) = 12*n  a(n1)  12 (with a(1)=5).  Vincenzo Librandi, Nov 16 2010
From R. J. Mathar, Oct 08 2011: (Start)
a(n) = 6*n  3  2*(1)^n.
G.f.: x*(5+2*x+5*x^2) / ( (1+x)*(x1)^2 ). (End)


CROSSREFS

Fifth row of A092260.
Sequence in context: A099389 A099382 A163633 * A003630 A122565 A247607
Adjacent sequences: A092239 A092240 A092241 * A092243 A092244 A092245


KEYWORD

nonn


AUTHOR

Giovanni Teofilatto, Feb 19 2004


EXTENSIONS

Edited and extended by Ray Chandler, Feb 21 2004


STATUS

approved



