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 A159354 Decimal expansion of 18 - 24*log(2). 1
 1, 3, 6, 4, 4, 6, 7, 6, 6, 6, 5, 6, 1, 3, 1, 2, 5, 7, 3, 9, 8, 6, 4, 2, 9, 0, 8, 5, 0, 0, 3, 7, 6, 2, 3, 6, 6, 1, 8, 7, 9, 9, 6, 7, 7, 5, 3, 5, 3, 8, 7, 3, 9, 0, 1, 1, 0, 3, 6, 7, 9, 7, 7, 2, 1, 5, 8, 5, 5, 3, 0, 7, 2, 7, 2, 7, 3 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The sum of the reciprocals of the nonnegative square pyramidal numbers (A000330). LINKS G. C. Greubel, Table of n, a(n) for n = 1..10000 E. Pérez Herrero, Square Pyramidal Numbers Reciprocals Sum, Psychedelic Geometry Blogspot pipi, How to evaluate sum_{n>=1} 1/(1^k+2^k+...+n^k) ?, math.stackexchange, Feb 28 2013 FORMULA Equals Sum_{k>=1} 1/(n*(n+1)*(2*n+1)/6). - Joerg Arndt, Dec 08 2013 MATHEMATICA Sum[1/Sum[i^2, {i, 1, k}], {k, 1, Infinity}] RealDigits[18-24*Log[2], 10, 100][[1]] (* G. C. Greubel, Jun 15 2018 *) PROG (PARI) 18 - 24*log(2) \\ G. C. Greubel, Jun 15 2018 (MAGMA) 18 - 24*Log(2); // G. C. Greubel, Jun 15 2018 CROSSREFS Cf. A000292. Sequence in context: A308291 A006464 A233825 * A196500 A023676 A318524 Adjacent sequences:  A159351 A159352 A159353 * A159355 A159356 A159357 KEYWORD cons,nonn AUTHOR Enrique Pérez Herrero, Apr 11 2009 STATUS approved

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Last modified December 11 01:07 EST 2019. Contains 329910 sequences. (Running on oeis4.)