|
Search: id:A109938
|
|
|
| A109938 |
|
Largest k-digit prime == 1 mod (prime(n)) where k is the number of digits in prime(n), or 0 if no such prime exists. |
|
+0
2
|
|
| 7, 7, 0, 0, 89, 79, 0, 0, 47, 59, 0, 0, 83, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 809, 619, 857, 0, 227, 509, 787, 823, 557, 0, 907, 0, 653, 0, 347, 359, 0, 383, 773, 0, 797, 0, 0, 0, 0, 467, 479, 0, 503, 0, 0, 0, 0, 0, 563, 0, 587, 0, 0, 0, 0, 0, 0, 0, 0, 0, 719, 0, 0, 0, 0, 0, 0, 0, 0
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
a(13) = 83 as prime(13) = 41 and 83 == 1 mod(41). 83 is the largest such two digit prime.
|
|
MAPLE
|
A055642 := proc(n) max(1, ilog10(n)+1) ; end: A109938 := proc(n) local p, k, a; p := ithprime(n) ; k := A055642(p) ; a := 0; q := numtheory[pi](10^(k-1)) ; q := ithprime(q+1) ; while A055642(q) < k+1 do if q mod p = 1 and q > a then a := q ; fi ; q := nextprime(q) ; od ; RETURN(a) ; end: seq(A109938(n), n=1..90) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2007
|
|
CROSSREFS
|
Sequence in context: A130553 A002394 A105167 this_sequence A019725 A064890 A046542
Adjacent sequences: A109935 A109936 A109937 this_sequence A109939 A109940 A109941
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 19 2005
|
|
EXTENSIONS
|
More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2007
|
|
|
Search completed in 0.002 seconds
|
