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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A143594 Triangle read by rows, A051731 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's). 1
 1, 2, 2, 2, 2, 2, 3, 4, 2, 2, 2, 2, 2, 2, 2, 4, 6, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 6, 4, 4, 2, 2, 2, 2, 3, 4, 4, 2, 2, 2, 2, 2, 2, 4, 6, 4, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 6, 10, 8, 6, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Left column = d(n), A000005: (1, 2, 2, 3, 2, 4, 2,...). Prime rows have all 2's. Row sums = A129235: (1, 4, 6, 11, 10, 10,...). LINKS Table of n, a(n) for n=1..91. FORMULA Triangle read by rows, A051731 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's), i.e. (1; 1,2; 1,2,2;...), 1<=k<=n A051731 = the inverse Mobius transform. EXAMPLE First few rows of the triangle = 1; 2, 2; 2, 2, 2; 3, 4, 2, 2; 2, 2, 2, 2, 2; 4, 6, 4, 2, 2, 2; 2, 2, 2, 2, 2, 2, 2; ... CROSSREFS Cf. A129235, A000005, A051731. Sequence in context: A242763 A018119 A177001 * A298949 A329097 A197054 Adjacent sequences: A143591 A143592 A143593 * A143595 A143596 A143597 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Aug 26 2008 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 November 29 03:03 EST 2023. Contains 367422 sequences. (Running on oeis4.)