OFFSET
1,1
REFERENCES
Chris K. Caldwill & G. L. Honaker, Jr., Prime Curios!, The Dictionary of Prime Number Trivia, CreateSpace, Sept. 2009, p. 145.
LINKS
Robin Visser, Table of n, a(n) for n = 1..1000
MATHEMATICA
del[m_, n_] := If[ Mod[n, m] == 0, 1, 0]; Int[n_] := If[n < 4, 0, Binomial[n, 4] + del[2, n] (-5n^3 + 45n^2 - 70n + 24)/24 - del[4, n] (3n/2) + del[6, n] (-45n^2 + 262n)/6 + del[12, n]*42n + del[18, n]*60n + del[24, n]*35n - del[30, n]*38n - del[42, n]*82n - del[60, n]*330n - del[84, n]*144n - del[90, n]*96n - del[120, n]*144n - del[210, n]*96n]; Select[ Range@ 759, PrimeQ@ Int@# &]
PROG
(Sage)
def is_A180686(k):
return Integer(binomial(k, 4) + (-5*k^3+45*k^2-70*k+24)*(k%2==0)/24
- 3*k*(k%4==0)/2 + (-45*k^2+262*k)*(k%6==0)/6 + 42*k*(k%12==0)
+ 60*k*(k%18==0) + 35*k*(k%24==0) - 38*k*(k%30==0)
- 82*k*(k%42==0) - 330*k*(k%60==0) - 144*k*(k%84==0)
- 96*k*(k%90==0) - 144*k*(k%120==0) - 96*k*(k%210==0)).is_prime()
print([k for k in range(1, 1000) if is_A180686(k)]) # Robin Visser, Jul 29 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 16 2010
EXTENSIONS
Name edited by Robin Visser, Jul 29 2024
STATUS
approved