A192283 Sum of prime anti-divisors of n = sum of prime anti-divisors of n+1 with n > 1.

237, 4019, 7401, 14178, 14339, 18435, 19146, 21405, 54562, 56348, 60125, 82967, 98447, 99347, 109157, 113391, 125333, 132096, 132386, 145063, 173399, 195213, 260288, 278271, 343848, 384169, 396813, 434375, 460758, 474105, 477707, 528845, 550400, 587211

Offset: 1

Author

Paolo P. Lava, Jul 27 2011

Keywords

• nonn

Comments

Like A006145 but using anti-divisors.

Examples

			Anti-divisors of 7401 are 2, 6, 19, 41, 113, 131, 361, 779, 4934. The primes are 2, 19, 41, 113 and 131 whose sum is 306.
Anti-divisors of 7402 are 3, 4, 5, 7, 9, 15, 21, 35, 45, 47, 63, 105, 113, 131, 141, 235, 315, 329, 423, 705, 987, 1645, 2115, 2961, 4935. The primes are 3, 5, 7, 47, 113 and 131 whose sum is 306.
		

Links

• Donovan Johnson, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A002961, A006145, A066272, A192282

Programs

Maple

with(numtheory);
P:=proc(n)
local a,b,i,k;
b:=2;
for i from 4 to n do
  a:=0;
  for k from 2 to i-1 do
    if abs((i mod k)- k/2) < 1 then if isprime(k) then a:=a+k; fi; fi;
  od;
  if a=b then print(i-1); fi;
  b:=a;
od;
end:
P(200000);