



0, 0, 1, 0, 0, 0, 1, 0, 0, 2, 1, 2, 0, 0, 3, 3, 4, 3, 4, 3, 3, 0, 0, 4, 4, 5, 4, 6, 5, 5, 3, 5, 5, 6, 4, 5, 4, 4, 0, 0, 5, 8, 9, 10, 13, 13, 15, 16, 17, 18, 18, 17, 17, 19, 19, 17, 17, 18, 18, 17, 16, 15, 13, 13, 10, 9, 8, 5, 0, 0, 6, 9, 14, 17, 18, 20, 22, 21
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OFFSET

0,10


COMMENTS

For all n>=2, a(1+A213710(n)) = n2.
Except for a(2)=1 (which seems to be the only negative term in the sequence), the sequences A218600 and A213710 give the positions of zeros.
Furthermore, each subrange [A213710(n)..A218600(n+1)] is palindromic. A233268 gives the middle points of those ranges, the sequence A234018 gives the values at those points, while A234019 gives the maximum term in that range in this sequence.


LINKS

Antti Karttunen, Rows 0..16, flattened


FORMULA

a(n) = A233271(n)  A179016(n).
a(A218602(n)) = a(n). [This is just a claim that each row is palindrome]


EXAMPLE

This irregular table begins as:
0;
0;
1;
0, 0;
0, 1, 0;
0, 2, 1, 2, 0;
0, 3, 3, 4, 3, 4, 3, 3, 0;
0, 4, 4, 5, 4, 6, 5, 5, 3, 5, 5, 6, 4, 5, 4, 4, 0;
...
After zero, each row n is A213709(n1) elements long.


PROG

(Scheme)
(define (A233270 n) ( (A233271 n) (A179016 n)))


CROSSREFS

Except for a(2)=1 (which seems to be the only negative term in the sequence), the sequences A218600 and A213710 give the positions of zeros.
Cf. A080468, A179016, A233271, A233268, A233274, A234018, A234019, A234020.
Sequence in context: A298902 A298963 A180760 * A241291 A317741 A317902
Adjacent sequences: A233267 A233268 A233269 * A233271 A233272 A233273


KEYWORD

sign,tabf


AUTHOR

Antti Karttunen, Dec 14 2013


STATUS

approved



