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A175033 Numbers n such that (ceiling(sqrt(n*n/2)))^2 - n*n/2 = 17/2. 0
9, 15, 55, 89, 321, 519, 1871, 3025, 10905, 17631, 63559, 102761, 370449, 598935, 2159135, 3490849, 12584361, 20346159, 73347031, 118586105, 427497825, 691170471 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Let (ceiling(sqrt(n*n/2)))^2 - n*n/2 = i. Then for i=1/2 we have A002315, for i=1 we have A005319, for i=2 we have A077444, for i=7/2 we have A077446, for i=4 we have A081554.
Conjecture: a(n) = 6*a(n-2) - a(n-4). - Charles R Greathouse IV, Apr 30 2016
LINKS
PROG
(PARI) lista(nn)=for (n=1, nn, if ((ceil(sqrt(n*n/2)))^2 - n*n/2 == 17/2, print1(n, ", ")); ); \\ Michel Marcus, Jun 02 2013
(PARI) forstep(n=9, 1e9, 2, if((sqrtint(n^2\2)+1)^2==(n^2+17)/2, print1(n", "))) \\ Charles R Greathouse IV, Apr 30 2016
CROSSREFS
Sequence in context: A039314 A146584 A276414 * A043137 A043917 A351499
KEYWORD
nonn,more
AUTHOR
Ctibor O. Zizka, Nov 09 2009
EXTENSIONS
More terms from Michel Marcus, Jun 02 2013
a(17)-a(22) from Charles R Greathouse IV, Apr 30 2016
STATUS
approved

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Last modified June 21 10:24 EDT 2024. Contains 373543 sequences. (Running on oeis4.)