

A154301


Primes of the form (1+2+...+m)/75 = A000217(m)/75.


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=75."
The corresponding mvalues are m=50,74,149,150. It is clear that for m>2*75, T(m)/75 = m(m+1)/150 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/75; If[Floor[s]==s, If[PrimeQ[s], AppendTo[lst, s]]], {n, 0, 3*9!}]; lst


PROG

(PARI) d=75*2; for(m=1, 999, (m^2+m)%d==0&isprime((m^2+m)/d)&print1(m", ")) \\ print the mvalues(!)  use A154304(75) to get A154301 as a vector. \\  M. F. Hasler, Jan 06 2013


CROSSREFS

Cf. A057570, A154293, A154296  A154304.
Sequence in context: A269240 A060429 A052292 * A057185 A157467 A093343
Adjacent sequences: A154298 A154299 A154300 * A154302 A154303 A154304


KEYWORD

nonn,fini,full,easy,bref


AUTHOR

Vladimir Joseph Stephan Orlovsky, Jan 06 2009


EXTENSIONS

Keywords fini,full added by R. J. Mathar, Aug 15 2010
Edited by M. F. Hasler, Jan 06 2013


STATUS

approved



