This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A265826 a(0) = 1, a(n) = Sum_{k=1..n, a(n-k)*ceiling(sin(k))} 1
 1, 1, 2, 4, 7, 13, 24, 45, 84, 157, 293, 547, 1021, 1906, 3558, 6642, 12399, 23146, 43208, 80659, 150571, 281080, 524709, 979506, 1828503, 3413376, 6371955, 11894912, 22204949, 41451316, 77379669, 144449290, 269652192, 503375992, 939682290 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS It appears that a(n) <= A088353(n). It is identical until n=11 where a(11) = 547, but A088353(n) = 548. It also appears that a(n) <= A059633(n+2). It is identical until n=25 where a(25) = 3413376, but A059633(27) = 3413377. LINKS Griffin N. Macris, Table of n, a(n) for n = 0..999 FORMULA a(0) = 1 a(n) = Sum_{k=1..n, a(n-k)*ceiling(sin(k))} EXAMPLE a(4) = 1*ceiling(sin(4)) + 1*ceiling(sin(3)) + 2*ceiling(sin(2)) + 4*ceiling(sin(1)) = 1*0 + 1*1 + 2*1 + 4*1 = 7 MATHEMATICA A[0] := 1 A[n_] := A[n] = If[n <= 0, 0, Sum[A[n - k]Ceiling[Sin[k]], {k, 1, n}]] PROG (Java) int limit = 500; //limit index, can be changed for more terms BigInteger[] n = new BigInteger[limit]; n[0] = BigInteger.ONE; System.out.println("0 1"); for ( int i = 1; i < n.length; i++ ) {    n[i] = BigInteger.ZERO;    for(int k = 1; k <= i; k++) {       n[i] = n[i].add(n[i-k].multiply(BigInteger.valueOf((long) Math.ceil(Math.sin(k)))));    }    System.out.println(i+" "+n[i]); } CROSSREFS Sequence in context: A005318 A102111 A224704 * A059633 A088353 A192654 Adjacent sequences:  A265823 A265824 A265825 * A265827 A265828 A265829 KEYWORD nonn,easy AUTHOR Griffin N. Macris, Apr 06 2016 STATUS approved

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