

A154302


Primes of the form (1+2+...+m)/87 = A000217(m)/87.


3




OFFSET

1,1


COMMENTS

Original definition: "Primes of the form : 1/x+2/x+3/x+4/x+5/x+6/x+7/x+..., x=87."
The corresponding mvalues are m=29,57,86,173. It is clear that for m>2*87, T(m)/87 = m(m+1)/174 cannot be a prime, since then each factor in the numerator is larger than the denominator. See A154304 for further comments and PARI code.  M. F. Hasler, Jan 06 2013


LINKS

Table of n, a(n) for n=1..4.


MATHEMATICA

lst={}; s=0; Do[s+=n/87; If[Floor[s]==s, If[PrimeQ[s], AppendTo[lst, s]]], {n, 0, 4*9!}]; lst


PROG

(PARI) d=87*2; for(m=1, 999, (m^2+m)%d==0&isprime((m^2+m)/d)&print1(m", ")) \\ print the mvalues(!)  use A154304(87) to get A154302 as a vector. \\  M. F. Hasler, Jan 06 2013


CROSSREFS

Cf. A057570, A154293, A154296  A154304.
Sequence in context: A172043 A146616 A146395 * A146736 A176358 A045458
Adjacent sequences: A154299 A154300 A154301 * A154303 A154304 A154305


KEYWORD

nonn,fini,full,easy,bref


AUTHOR

Vladimir Joseph Stephan Orlovsky, Jan 06 2009


EXTENSIONS

Edited by M. F. Hasler, Jan 06 2013


STATUS

approved



