An imperial crown above a central circular hole with a scroll ornament to right and left; below crown and around the hole, the denomination ONE HALFPENNY; around, outside the scroll ornaments, the legend GEORGIVS V REX ET IND: IMP: (George the Fifth, King and Emperor of India); below the hole, the denomination in Arabic: نُصْف پَنّي.
The mint mark (if any) is between the centre hole and the Arabic inscription.
Around circular central hole, Solomon's seal (six-pointed "Star of David"), consisting of two equilateral triangles interlaced; around above, BRITISH WEST AFRICA; below, the star divides the date 1913.
Remick does not list Royal Mint halfpennies for 1913, and lists 1,622,400 for the next year (1914), while Krause lists 1,382,000 Royal Mint halfpennies for 1913 and 240,000 for 1914 - which seems to be the correct numbers.
CoinFactsWiki says that the Royal Mint issue is a "rare date that is unknown in uncirculated grade according to specialists, while the Heaton Mint issue is common even though it has a much lower mintage".