|
| |
|
|
A147806
|
|
Partial sums of A147809(n)=tau(n^2+1)/2-1.
|
|
2
| |
|
|
0, 0, 1, 1, 2, 2, 4, 5, 6, 6, 7, 8, 11, 11, 12, 12, 15, 17, 18, 18, 21, 22, 25, 25, 26, 26, 29, 30, 31, 32, 35, 37, 40, 41, 42, 42, 45, 47, 48, 48, 50, 51, 56, 57, 58, 59, 66, 67, 68, 69, 70, 71, 74, 74, 77, 77, 84, 85, 86, 87, 88, 89, 92, 93, 94, 94, 97, 100, 101, 103, 104, 107
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,5
|
|
|
COMMENTS
| It seems that a(10^n) = (6,168,2754,38561,495569,...) ~ 1.1*(n-0.5)*10^n, otherwise said a(n) ~ 1.1*(log10(n)-0.5)*n, asymptotically.
|
|
|
FORMULA
| a(n) = A147807(n) - n
|
|
|
PROG
| (PARI) s=0; a147806=vector(99, n, s+=numdiv(n^2+1))/2
A147806(n)=sum(p=1, n, numdiv(n^2+1))/2-n
|
|
|
CROSSREFS
| Cf. A147807, A147809-A147811.
Sequence in context: A181523 A181537 A130498 * A064574 A059015 A024683
Adjacent sequences: A147803 A147804 A147805 * A147807 A147808 A147809
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| M. F. Hasler (www.univ-ag.fr/~mhasler), Dec 13 2008
|
| |
|
|
