OFFSET
1,1
COMMENTS
Also primes of the form n^3 + 3/2*n^2 + 1/2*n + 1.
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 613: T(8)+S(8)+C(8)+1 = 1/2*8*(8+1)+8^2+8^3+1 = 613 which is prime.
a(4) = 1951: T(12)+S(12)+C(12)+1 = 1/2*12*(12+1)+12^2+12^3+1 = 1951 which is prime.
MAPLE
KD:= proc() local a, b, c, d; a:= (1/2)*n*(n+1); b:=n^2; c:=n^3; d:=a+b+c+1; if isprime(d) then RETURN(d): fi; end:seq(KD(), n=1..500);
PROG
(PARI) select(isprime, vector(100, n, n^3+3/2*n^2+n/2+1)) \\ Charles R Greathouse IV, Sep 15 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, Sep 14 2013
STATUS
approved