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

Author

Russ Cox

Keywords

• dumb
• easy
• nonn

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

Examples

			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.
		

Links

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

Crossrefs

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

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