A067229 Numbers n such that phi(2n+1)=sigma(n).

6, 7, 27, 38, 55, 85, 87, 127, 188, 236, 255, 266, 445, 451, 655, 717, 913, 1309, 1357, 1490, 1947, 2095, 2515, 2726, 3002, 3247, 3289, 4117, 4237, 5071, 5605, 7195, 8924, 12128, 12625, 12771, 12837, 13190, 13795, 15835, 16197, 16748, 17997, 20257