|
| |
|
|
A118064
|
|
Decimal expansion of the sum of the reciprocals of the palindromic primes (Honaker's constant).
|
|
0
| | |
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| The sum using all palindromic numbers <10^11 is 1.32398... Extrapolating using palindromic primes <10^8 using Wynn's epsilon method gives a value near 1.3240... - Eric Weisstein (eric(AT)weisstein.com), May 14 2006
|
|
|
LINKS
| Carlos Rivera: Problems & Puzzles: Puzzle 056 - The Honaker's Constant.
Eric Weisstein: Palindromic Prime.
|
|
|
FORMULA
| a(n) = sum(1/p), p is a palindromic prime.
|
|
|
MATHEMATICA
| (* first obtain nextPalindrome from A007632 *) s = 1/11; c = 1; pp = 1; Do[ While[pp < 10^n, If[PrimeQ@ pp, c++; s = N[s + 1/pp, 64]]; pp = NextPalindrome@ pp]; If[ OddQ@ n, pp = 10^(n + 1); Print[{s, n, c}]], {n, 17}] [From Robert G. Wilson v (rgwv(AT)rgwv.com), May 31 2009]
|
|
|
CROSSREFS
| Cf. A002385, A160910.
Cf. A050251. [From Robert G. Wilson v (rgwv(AT)rgwv.com), May 31 2009]
Sequence in context: A089750 A109591 A143932 * A070471 A070690 A160387
Adjacent sequences: A118061 A118062 A118063 * A118065 A118066 A118067
|
|
|
KEYWORD
| cons,base,nonn,hard,more
|
|
|
AUTHOR
| Martin Renner (martin.renner(AT)gmx.net), May 11 2006
|
|
|
EXTENSIONS
| Corrected by Eric Weisstein (eric(AT)weisstein.com), May 14 2006
|
| |
|
|
