A144136 (0=0, 1=1, 2=2, 3=3, 4=2^2, 5=5, 6=2*3, 7=7, 8=2^3, 9=3^2, 10=2*5, 11=11, 12=2^2*3, ...) becomes (0+0+1, 1+2+2, 3+3+4, 2+2+5, 5+6+2, 3+7+7, 8+2+3, 9+3+2, 10+2+5, 11+11+12, 2+2+3, ...).

1, 5, 10, 9, 13, 17, 13, 14, 17, 34, 7, 40, 24, 24, 23, 37, 24, 41, 28, 32, 36, 49, 31, 33, 42, 34, 11, 88, 10, 94, 40, 48, 54, 48, 7, 76, 59, 55, 45, 87, 47, 93, 48, 59, 53, 72, 97, 56, 59, 9, 71, 56, 119, 59, 63, 69, 67, 80, 90, 121, 10, 184, 96, 12, 72, 83, 71, 145, 72, 89, 95

Offset

1,2

Links

Table of n, a(n) for n=1..71.

Example

2 + 2 + 3 = 7 = a(11),
13 + 13 + 14 = 40 = a(12),
2 + 7 + 15 = 24 = a(13),
3 + 5 + 16 = 24 = a(14),
2 + 4 + 17 = 23 = a(15),
17 + 18 + 2 = 37 = a(16),
3 + 2 + 19 = 24 = a(17),
etc.

Maple

pflat := proc(nmax) local a, ifs, n, p, c ; a := [0, 0, 1, 1] ; for n from 2 to nmax do a := [op(a), n] ; ifs := ifactors(n)[2] ; for p in ifs do a := [op(a), op(1, p)] ; if op(2, p) > 1 then a := [op(a), op(2, p)] ; fi; od: od: a ; end: L := pflat(300) ; for n from 1 to nops(L)-3 by 3 do printf("%d, ", op(n, L)+op(n+1, L)+op(n+2, L) ) ; end do: # R. J. Mathar, Apr 29 2010

Crossrefs

Cf. A002808, A136740, A136811, A143716.

Sequence in context: A316707 A109360 A141622 * A343852 A198286 A001483

Adjacent sequences: A144133 A144134 A144135 * A144137 A144138 A144139

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 17 2008

Extensions

All numbers after a(14) corrected by R. J. Mathar, Apr 29 2010

Status

approved