|
Search: id:A074809
|
|
|
| A074809 |
|
Largest prime factor of A019518, concatenation of first n primes. |
|
+0
5
|
|
| 2, 23, 47, 2357, 223, 35339, 214282847, 7717859, 806801, 185176472401, 357211, 4967701595369, 104364752351, 27558919, 5269410931806332951, 274784055330749, 1191126125288819, 178258515898000387, 2313161253378144566969023310693, 8730041915527145606449758346652473, 26293517701186435480644832888393, 29890227360205834316383307128051, 3858432486690092813, 7122852423207105431971, 93753283248830261744671
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
n=5: concatenation of {2,3,5,7,11} is 235711=7.151.223, largest prime divisor is a(5)=223.
|
|
MATHEMATICA
|
<<NumberTheory`NumberTheoryFunctions` sz[x_] :=FromDigits[Flatten[Table[IntegerDigits[Prime[j]], {j, 1, x}], 1]] Table[Max[PrimeFactorList[sz[w]]], {w, 1, 25}] (Labos)
|
|
CROSSREFS
|
Cf. A019158.
Sequence in context: A139831 A049592 A057621 this_sequence A084237 A106928 A070934
Adjacent sequences: A074806 A074807 A074808 this_sequence A074810 A074811 A074812
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Jason Earls (zevi_35711(AT)yahoo.com), Sep 08 2002
|
|
EXTENSIONS
|
More terms from Labos E. (labos(AT)ana.sote.hu), Mar 18 2005
|
|
|
Search completed in 0.002 seconds
|
