|
Search: id:A145898
|
|
|
| A145898 |
|
Ending prime: where number of consecutive squares m^2 satisfy r=p+4*m^2, prime |
|
+0
3
|
|
| 37, 151, 29, 23, 293, 107, 263, 83, 113, 107, 113, 131, 1607, 197, 239, 233, 313, 311, 317, 353, 383, 401, 443, 461, 499, 523, 503, 617, 659, 677, 743, 773, 773, 887, 857, 863, 881, 887, 911, 953, 983, 1013, 1283, 1129, 1277, 1283, 1301, 1319, 1619, 1433
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Farideh Firoozbakht noticed the unusually high number of 19 primes ending in a(13)=1607 in A145741 where she specified an m sequence of 1 . . . 10. My m sequence is open. 1,2,3, . . ., m+1, all squared.
|
|
EXAMPLE
|
a(1)=37 because when m is 3, first prime is 5 and ending prime is 37: r=1+4*1^1=5, prime; and r=1+4*2^2=17, prime; and r=1+4*3^2=37, prime (and the next value of r does not produce a prime).
|
|
PROGRAM
|
(Other) UBASIC: 10 'p464 20 N=1 30 A=3:S=sqrt(N) 40 B=N\A 50 if B*A=N then 100 60 A=A+2 70 if A<=S then 40 80 M=M+1:R=N+4*M^2:if R=prmdiv(R) and M<100 then print N; R; M:goto 80 90 if M>=1 then stop 100 M=0:N=N+2:goto 30
|
|
CROSSREFS
|
A145896 A145897 A145741
Sequence in context: A157324 A141968 A142656 this_sequence A096700 A158596 A142688
Adjacent sequences: A145895 A145896 A145897 this_sequence A145899 A145900 A145901
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Enoch Haga (Enokh(AT)comcast.net), Oct 25 2008
|
|
|
Search completed in 0.002 seconds
|
