(n+2)^31 - n^31
2 (31 n^30+930 n^29+17980 n^28+251720 n^27+2718576 n^26+23560992 n^25+168292800 n^24+1009756800 n^23+5160979200 n^22+22708308480 n^21+86704450560 n^20+289014835200 n^19+844812595200 n^18+2172375244800 n^17+4924050554880 n^16+9848101109760 n^15+17379001958400 n^14+27034003046400 n^13+36993898905600 n^12+44392678686720 n^11+46506615767040 n^10+42278741606400 n^9+33087710822400 n^8+22058473881600 n^7+12352745373696 n^6+5701267095552 n^5+2111580405760 n^4+603308687360 n^3+124822487040 n^2+16642998272 n+1073741824)