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A228552 Square root of the absolute value of A069191(n). 9
1, 1, 1, 0, 1, 1, 2, 2, 0, 0, 0, 0, 0, 0, 0, 2, 2, 3, 5, 11, 8, 24, 48, 60, 56, 16, 12, 31, 155, 217, 588, 1148, 328, 164, 176, 132, 176, 395, 277, 697, 692, 191, 915, 76, 22742, 125664, 128079, 213885, 7371, 171654, 89678, 114902, 149465, 353497, 144573, 388325, 198676, 1738118, 1311164, 222898 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

According to the comments of A069191, a(n) should be always integral. Note that a(2*n) is the absolute value of A228616(n) by the comments of A228591. We conjecture that a(n) > 0 for all n > 15.

LINKS

Zhi-Wei Sun, Table of n, a(n) for n = 1..400

MATHEMATICA

a[n_]:=a[n]=Sqrt[Abs[Det[Table[If[PrimeQ[i+j]==True, 1, 0], {i, 1, n}, {j, 1, n}]]]]

Table[a[n], {n, 1, 20}]

CROSSREFS

Cf. A000040, A069191, A228616, A228615, A228548, A228549.

Sequence in context: A098940 A098939 A180215 * A240066 A240067 A300717

Adjacent sequences:  A228549 A228550 A228551 * A228553 A228554 A228555

KEYWORD

nonn

AUTHOR

Zhi-Wei Sun, Aug 25 2013

STATUS

approved

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Last modified January 21 01:45 EST 2022. Contains 350473 sequences. (Running on oeis4.)