A176660 Partial sums of A038772.

23, 50, 79, 113, 150, 188, 231, 277, 324, 373, 426, 480, 536, 593, 651, 710, 777, 845, 914, 987, 1061, 1137, 1215, 1294, 1377, 1463, 1550, 1639, 1733, 1830, 1928, 2131, 2338, 2547, 2770, 2997, 3226, 3459, 3698, 3945, 4194, 4447, 4704, 4963, 5226, 5493

Offset: 1

Author

Jonathan Vos Post, Apr 23 2010

Keywords

• base
• easy
• nonn

Comments

Partial sums of numbers not divisible by any of their digits. The partial sums of the complement (A038770, numbers divisible by at least one of their digits) is A176659. Hence the sum of the two partial sums (properly offset) is triangular numbers A000217. The subsequence of primes in the partial sum begins: 23, 79, 113, 277, 373, 593, 1061, 1733, 2131, 4447, 9479. The smallest square in the sequence is 324.

Examples

			a(4) = 23 + 27 + 29 + 34 = 113 is prime.
		

Crossrefs

Cf. A038772, 034709, A034837, A038769, A038770, A176659.

Formula

a(n) = SUM[i=1..n] A038772(i).