|
| |
|
|
A089294
|
|
Smallest prime p_k such that n can be written as a "plus-minus" sum n=sum_(i=1..k)e_i*(p_i)^2 with distinct primes p_i<=p_k, where e_i is 1 or -1.
|
|
3
| |
|
|
19, 13, 19, 13, 2, 3, 13, 19, 13, 3, 13, 7, 5, 3, 13, 7, 5, 13, 13, 7, 5, 5, 13, 13, 7, 5, 13, 13, 7, 5, 5, 13, 13, 7, 5, 13, 7, 7, 5, 13, 7, 17, 11, 11, 7, 7, 17, 11, 13, 7, 17, 11, 11, 7, 7, 17, 11, 13, 7, 11, 11, 7, 7, 11, 13, 7, 17, 11, 11, 7, 7, 17, 11, 13, 7, 17, 11, 11, 7, 7, 17, 11
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
COMMENTS
| The first terms where this sequence differs from A088934 are n=22,31,52,87,89,98,118,127,...
|
|
|
EXAMPLE
| a(22)=13 because 22 can be represented as -13^2+11^2+7^2+5^2-2^2.
The corresponding representation with the minimum number of terms is
22=19^2-13^2-11^2-7^2 (A088934(22)=19, A088910(22)=4 terms)
|
|
|
CROSSREFS
| The positions of the records in this sequence are given in A089295. Cf. A088910, A088934.
Sequence in context: A083156 A040344 A196188 * A088934 A177923 A155848
Adjacent sequences: A089291 A089292 A089293 * A089295 A089296 A089297
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| W. Edwin Clark (eclark(AT)math.usf.edu) Nov 06 2003
|
| |
|
|
