A247084 a(n)=0 when n<=0: Starting with n=1, a(n) = 1 + the sum of the digital sums of a(0) through a(n-4).

0, 1, 1, 1, 1, 2, 3, 4, 5, 7, 10, 14, 19, 26, 27, 32, 42, 50, 59, 64, 70, 75, 89, 99, 106, 118, 135, 153, 160, 170, 179, 188, 195, 203, 220, 237, 252, 257, 261, 273, 282, 296, 305, 317, 329, 346, 354, 365, 379, 392, 404, 418, 437, 451, 459, 472, 486, 496, 514

Offset

0,6

Links

Table of n, a(n) for n=0..58.

Eric Angelini, a(n) > cumulative sum of digits, Seqfan, Nov. 11, 2014.

Formula

a(n) = 1 + Sum_{k=0..n-4} digsum(a(k)).

a(n) = a(n-1) + digsum(a(n-4)).

Example

a(15) = 32 because (0+1+1+1+1+2+3+4+5+7+1+0+1+4) + 1 = 32.

Mathematica

a247084[n_Integer] := Module[{t = Table[1, {i, n + 1}], j, k},
t[[1]] = 0; j = 6; While[j <= Length[t], t[[j]] = Sum[Plus @@ IntegerDigits[t[[k]]], {k, 1, j - 4}]; ++]; Drop[t, {2}]]; a247084[59] (* Michael De Vlieger, Nov 29 2014 *)

Prog

(PARI) lista(nn) = {v = vector(nn); for (n=2, nn, v[n] = 1 + sum(i=1, n-4, if (n-4 > 0, sumdigits(v[i]))); ); v; } \\ Michel Marcus, Nov 18 2014

Crossrefs

Cf. A007953, A219675, A244510 (related).

Sequence in context: A321481 A238874 A099559 * A017898 A003269 A367794

Adjacent sequences: A247081 A247082 A247083 * A247085 A247086 A247087

Keyword

base,nonn

Author

Bob Selcoe, Nov 17 2014

Extensions

More terms from Michel Marcus, Nov 18 2014

Status

approved