Self-convolution equals A183160.

Terms

a(0) =1a(1) =1a(2) =5a(3) =26a(4) =145a(5) =841a(6) =5006a(7) =30350a(8) =186537a(9) =1158685a(10) =7258145a(11) =45779420a(12) =290399030a(13) =1851032314a(14) =11847434810a(15) =76100034106a(16) =490343021881