A039928 Sum of first n terms of A_n (using absolute values of terms).

0, 3, 3, 0, 10, 12, 1, 24, 25, 32, 116, 12, 412, 109, 126, 2389, 12497, 28772, 126, 72795, 247786, 770213, 159378001963452599318, 2169128, 442, 311, 378, 789, 10015050, 75, 74253544, 7881195, 2461717833658872781238383813854943728, 51, 17, 824, 855, 2, 29981, 3087, 215308, 123456790123456790123456790123456790123452, 132813776, 1086162642, 1836311902, 400276874544

Offset

1,2

Comments

Since the sequences in the OEIS occasionally change their initial terms (for editorial reasons), this is an especially ill-defined sequence! - N. J. A. Sloane, Jan 01 2005

The next term, a(47), is currently unknown. - Jianing Song, Oct 07 2018

Links

Table of n, a(n) for n=1..46.

Index entries for sequences whose definition involves A_n (or An).

Example

A000001 (Number of groups of order n) begins 0,... -> a(1) = 0
A000002 (Kolakoski sequence) begins 1, 2,... -> a(2) = 3
A000003 begins 1, 1, 1,... -> a(3) = 3
A000004 (The zero sequence) begins 0, 0, 0, 0,... -> a(4) = 0
A000005 (The number of divisors) begins 1, 2, 2, 3, 2, ... -> a(5) = 10
...
A000010 (Euler totient function) begins 1, 1, 2, 2, 4, 2, 6, 4, 6, ... so a(10) = 1 + 1 + 2 + 2 + 4 + 2 + 6 + 4 + 6 + 4 = 32.

Crossrefs

Cf. A031135, A031214, A100543 (uses signed values).

Sequence in context: A298850 A262292 A100543 * A374828 A247889 A309012

Adjacent sequences: A039925 A039926 A039927 * A039929 A039930 A039931

Keyword

dumb,easy,nonn

Author

Russ Cox

Extensions

Corrected and extended by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 27 2004

a(1) changed from 1 to 0 and extended by Jianing Song, Oct 06 2018

Status

approved