login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A125004 a(0) = 9; for n>0, a(n) is determined by the rule that the concatenation of the leading terms of the difference triangle is the same as the concatenation of the digits of the sequence. 2
9, 10, 11, 13, 18, 30, 59, 129, 299, 717, 1741, 4183, 9781, 22123, 48516, 103856, 218683, 455839, 944616, 1950404, 4016865, 8257883, 16962086, 34853986, 71735687, 148017585, 306239910, 634872376, 1316958592, 2728411246 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

a(0) = 9; binomial transform of sequence gives successive digits of sequence.

LINKS

Table of n, a(n) for n=0..29.

N. J. A. Sloane, Transforms

MAPLE

revert := proc(n) local Linv, i, L ; L := convert(n, base, 10) ; Linv := [] ; for i from 1 to nops(L) do Linv := [op(Linv), op(-i, L)] ; od ; RETURN(Linv) ; end: A125004 := proc(nmax) local ldigs, T, diag, row ; T := array(1..nmax, 1..nmax) ; ldigs := [9, 1, 0] ; T[1, 1] := ldigs[1] ; for diag from 2 to nmax do T[diag, 1] := ldigs[diag] ; for row from diag-1 to 1 by -1 do T[row, diag-row+1] := T[row, diag-row]+T[row+1, diag-row] ; od ; if diag > 2 then ldigs := [op(ldigs), op(revert(T[1, diag])) ] ; fi ; od ; RETURN(T) ; end : nmax := 50 : T := A125004(nmax) : for i from 1 to nmax do printf("%d, ", T[1, i]) ; od ; # R. J. Mathar, Jan 10 2007

CROSSREFS

Cf. A125588, A125003, A125591.

Sequence in context: A031047 A120193 A134534 * A085514 A086446 A168042

Adjacent sequences:  A125001 A125002 A125003 * A125005 A125006 A125007

KEYWORD

nonn,easy,base

AUTHOR

N. J. A. Sloane, Jan 08 2007

EXTENSIONS

More terms from R. J. Mathar, Jan 10 2007

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 16:08 EDT 2019. Contains 322461 sequences. (Running on oeis4.)