|
Search: id:A109928
|
|
|
| A109928 |
|
Least k such that there are n primes of the form kr+1 with 1<=r<=k. Indices of the first occurrence of n in A085053. |
|
+0
1
|
|
| 1, 2, 4, 13, 6, 10, 20, 47, 22, 18, 28, 34, 51, 40, 62, 36, 30, 50, 48, 74, 42, 82, 80, 54, 105, 72, 60, 147, 78, 66, 116, 134, 84, 96, 142, 146, 108, 90, 114, 102, 172, 206, 130, 160, 226, 120, 144, 138, 126, 196, 248, 262, 162, 170, 302, 156, 186, 274, 356, 174
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
EXAMPLE
|
a(6) = 10 as 10 is the least number that gives 6 primes of the form 10k +1, k<=10. (11,31,41,61,71,101).
|
|
MATHEMATICA
|
t=Table[Length[Select[Range[n], PrimeQ[n#+1]&]], {n, 1000}]; Table[First[Flatten[Position[t, n]]], {n, 100}] (Noe)
|
|
CROSSREFS
|
Cf. A085053 (number of primes of the form kn+1, with k<=n).
Sequence in context: A053040 A059085 A030064 this_sequence A023640 A064454 A064461
Adjacent sequences: A109925 A109926 A109927 this_sequence A109929 A109930 A109931
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 17 2005
|
|
EXTENSIONS
|
More terms from T. D. Noe (noe(AT)sspectra.com), Jul 17 2005
|
|
|
Search completed in 0.002 seconds
|
