A140131 a(n) = a(n-1) + a(n-2) + digsum(a(n-1)) + digsum(a(n-2)), with a(0)=0 and a(1)=1.

0, 1, 2, 6, 16, 35, 66, 121, 203, 333, 550, 902, 1473, 2401, 3896, 6330, 10264, 16619, 26919, 43588, 70562, 114198, 184804, 299051, 483906, 783013, 1266971, 2050038, 3317059, 5367143, 8684259, 14051473, 22735799, 36787341, 59523223, 96310634, 155833920, 252144622

Offset

0,3

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Maple

P:=proc(n) local i, t; t:=[0, 1]; for i from 1 to n do t:=[op(t), t[-2]+t[-1]+convert(convert(t[-2], base, 10), `+`)+convert(convert(t[-1], base, 10), `+`)]; od; print(op(t)); end: P(34); # Paolo P. Lava, Jun 25 2024

Mathematica

nxt[{a_, b_}]:=a+b+Total[IntegerDigits[a]]+Total[IntegerDigits[b]]; Transpose[NestList[{Last[#], nxt[#]}&, {0, 1}, 40]][[1]] (* Harvey P. Dale, Oct 31 2011 *)

Crossrefs

Cf. A007953, A016052, A047892, A047897-A047900, A047902, A047903, A055263, A134268, A135210, A140132.

Sequence in context: A199477 A330884 A060354 * A159938 A325743 A254119

Adjacent sequences: A140128 A140129 A140130 * A140132 A140133 A140134

Keyword

easy,nonn,base

Author

Paolo P. Lava and Giorgio Balzarotti, May 09 2008

Status

approved