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A172524
Partial sums of Iccanobif numbers A001129.
0
0, 1, 2, 4, 7, 12, 20, 33, 72, 196, 710, 1546, 2599, 6738, 19553, 80688, 185625, 978142, 2432840, 12112678, 29466988, 39202128, 40962878, 41948928, 42570288, 42684103, 43265540, 44518036, 52194742, 65214030, 159581828, 337649208
OFFSET
0,3
COMMENTS
The only primes in this sequence are: 2, 7 and 19553. The squares in this sequence begin: 0, 1, 4, 196.
FORMULA
a(n) = SUM[i=0..n] A001129(i) = SUM[i=0..n] {a(0) = 0, a(1) = 1, a(i+2) = R(a(i)) + R(a(i+1))} = SUM[i=0..n] A001129(i) = SUM[i=1..n] {a(0) = 0, a(1) = 1, a(i+2) = A004086(a(i)) + A004086(a(i+1))}.
EXAMPLE
a(14) = 0 + 1 + 1 + 2 + 3 + 5 + 8 + 13 + 39 + 124 + 514 + 836 + 1053 + 4139 + 12815 = 19553 is prime. a(31) = 0 + 1 + 1 + 2 + 3 + 5 + 8 + 13 + 39 + 124 + 514 + 836 + 1053 + 4139 + 12815 + 61135 + 104937 + 792517 + 1454698 + 9679838 + 17354310 + 9735140 + 1760750 + 986050 + 621360 + 113815 + 581437 + 1252496 + 7676706 + 13019288 + 94367798 + 178067380.
MATHEMATICA
nxt[{a_, b_}]:={b, Total[FromDigits/@Reverse/@IntegerDigits[{a, b}]]}; Accumulate[ Transpose[NestList[nxt, {0, 1}, 40]][[1]]] (* Harvey P. Dale, Apr 04 2015 *)
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Feb 06 2010
STATUS
approved