A176718 Partial sums of A004207.

1, 2, 4, 8, 16, 32, 55, 83, 121, 170, 232, 302, 379, 470, 571, 674, 781, 896, 1018, 1145, 1282, 1430, 1591, 1760, 1945, 2144, 2362, 2591, 2833, 3083, 3340, 3611, 3892, 4184, 4489, 4802, 5122, 5447, 5782, 6128, 6487, 6863, 7255, 7661, 8077, 8504, 8944, 9392

Offset

0,2

Comments

Partial sums of a(1) = 1, a(n) = sum of digits of all previous terms. The subsequence of primes in this sequence begins: 2, 83, 379, 571, 2591, 2833, 3083, 6863, 10831. The subsequence of squares in this sequence begins: 1, 4, 16, 121, 4489.

Links

Table of n, a(n) for n=0..47.

Formula

a(n) = SUM[i=0..n] A004207(i) = SUM[i=0..n] {b(1) = 1, b(j) = sum of digits of b(j) for j = 0..i} = SUM[i=0..n] {b(1) = 1, b(k) = A007953(b(k)) for k = 0..i}.

Example

a(7) = 1 + 1 + 2 + 4 + 8 + 16 + 23 + 28 = 83 is prime.

Maple

A176718 := proc(n)
    add( A004207(k), k=0..n) ;
end proc: # R. J. Mathar, Apr 02 2014

Crossrefs

Cf. A004207, A016052, A033298, A007612.

Sequence in context: A007055 A175951 A072207 * A033860 A374731 A374733

Adjacent sequences: A176715 A176716 A176717 * A176719 A176720 A176721

Keyword

base,easy,nonn

Author

Jonathan Vos Post, Apr 25 2010

Status

approved