A173496 Partial sums of A005036.

1, 2, 4, 9, 25, 85, 346, 1589, 7846, 40567, 216327, 1180227, 6554627, 36939883, 210777514, 1215644593, 7077255068, 41546269583, 245708229893, 1462853468378, 8761861115930, 52767463557770

Offset: 1

Author

Jonathan Vos Post, Feb 19 2010

Keywords

• nonn

Comments

Partial sums of number of ways of dissecting a polygon into n quadrilaterals. The subsequence of primes in this partial sum begins: 2, 6554627, 36939883, 1215644593.

Examples

			a(22) = 1 + 1 + 2 + 5 + 16 + 60 + 261 + 1243 + 6257 + 32721 + 175760 + 963900 + 5374400 + 30385256 + 173837631 + 1004867079 + 5861610475 + 34469014515 + 204161960310 + 1217145238485 + 7299007647552 + 44005602441840.
		

Crossrefs

Cf. A005036, A005419, A004127, A005038, A005040, A000207.

Formula

a(n) = SUM[i=1..n] A005036(i).