The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A111033 Sum of squares of first n digits of Pi. 2
 9, 10, 26, 27, 52, 133, 137, 173, 198, 207, 232, 296, 377, 426, 507, 516, 520, 529, 593, 609, 645, 649, 685, 701, 710, 719, 783, 792, 796, 845, 926, 951, 951, 955, 1019, 1083, 1099, 1100, 1181, 1230, 1231, 1267, 1348, 1357, 1438, 1519, 1528, 1577, 1602 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) is prime for n = 7, 8, 19, 24, 26, ... a(n) is semiprime for n = 1, 2, 3, 6, 13, 18, 22, 23, ... a(n) is a perfect power for n = 1, 4, 18, ... LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA a(n) = Sum_{i=1..n} A000796(i)^2. EXAMPLE a(1) = 3^2 = 9, a(2) = 3^2 + 1^2 = 10, a(3) = 3^2 + 1^2 + 4^2 = 26, a(4) = 3^2 + 1^2 + 4^2 + 1^2 = 27, a(5) = 3^2 + 1^2 + 4^2 + 1^2 + 5^2 = 52, a(6) = 3^2 + 1^2 + 4^2 + 1^2 + 5^2 + 9^2 = 133, a(7) = 3^2 + 1^2 + 4^2 + 1^2 + 5^2 + 9^2 + 2^2 = 137, which is prime. MAPLE Digits := 120 ; A000796 := proc(n) floor(Pi*10^(n-1)) ; % mod 10 ; end proc: A111033 := proc(n) add( A000796(i)^2, i=1..n) ; end proc: seq(A111033(n), n=1..120) ; # R. J. Mathar, Dec 21 2010 MATHEMATICA Accumulate[RealDigits[Pi, 10, 50][[1]]^2] (* Harvey P. Dale, Jul 18 2021 *) PROG (Sage) A111033 = lambda n: sum(d**2 for d in floor(pi*10**(n-1)).digits()) # D. S. McNeil Dec 22 2010 CROSSREFS Cf. A000796. Sequence in context: A156787 A025043 A320728 * A123048 A189047 A041170 Adjacent sequences:  A111030 A111031 A111032 * A111034 A111035 A111036 KEYWORD base,easy,nonn AUTHOR Jonathan Vos Post, Oct 05 2005 EXTENSIONS More terms from Vincenzo Librandi, Dec 21 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 3 18:10 EDT 2022. Contains 355055 sequences. (Running on oeis4.)