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A347341
Decimal expansion of (Pi^2-3)/12.
1
5, 7, 2, 4, 6, 7, 0, 3, 3, 4, 2, 4, 1, 1, 3, 2, 1, 8, 2, 3, 6, 2, 0, 7, 5, 8, 3, 3, 2, 3, 0, 1, 2, 5, 9, 4, 6, 0, 9, 4, 7, 4, 9, 5, 0, 6, 0, 3, 3, 9, 9, 2, 1, 8, 8, 6, 7, 7, 7, 9, 1, 1, 4, 6, 8, 5, 0, 0, 3, 7, 3, 5, 2, 0, 1, 6, 0, 0, 4, 3, 6, 9, 1, 6, 8, 1
OFFSET
0,1
FORMULA
Equals (Pi^2-3)/12 = A126561 + 1/2 = A072691 - 1/4.
Equals Sum_{k=1..infinity} (-1)^(k+1)*cos(k)/k^2.
EXAMPLE
0.57246703342411321823620758332301259460947495060...
MATHEMATICA
RealDigits[(Pi^2-3)/12, 10, 120][[1]] (* Harvey P. Dale, Jun 06 2022 *)
PROG
(PARI) sumalt(k=1, (-1)^(k+1)*cos(k)/k^2) \\ Hugo Pfoertner, Aug 27 2021
CROSSREFS
Cf. A000796.
Almost the same as A072691, A126561.
Sequence in context: A021640 A155968 A154479 * A153110 A099283 A368663
KEYWORD
nonn,cons
AUTHOR
Paolo Xausa, Aug 27 2021
STATUS
approved