A246349 Positions of records in A246272.

1, 2, 6, 10, 30, 42, 210, 330, 462, 2310, 6090, 30030, 66990, 94710, 434910, 651630, 1292646, 1610070, 2478630, 2497110, 2916690, 13220130, 20930910, 52582530, 60690630

Offset: 1

Author

Antti Karttunen, Aug 23 2014

Keywords

• nonn

Comments

All terms are squarefree. (See the comments in A246272).

From 2 onward they factorize as: 2, 2*3, 2*5, 2*3*5, 2*3*7, 2*3*5*7, 2*3*5*11, 2*3*7*11, 2*3*5*7*11, 2*3*5*7*29, 2*3*5*7*11*13, 2*3*5*7*11*29, 2*3*5*7*11*41, 2*3*5*7*19*109, 2*3*5*7*29*107, 2*3*17*19*23*29, 2*3*5*7*11*17*41, 2*3*5*7*11*29*37, 2*3*5*7*11*23*47, 2*3*5*7*17*19*43, 2*3*5*7*11*59*97, 2*3*5*7*11*13*17*41, 2*3*5*7*11*13*17*103, 2*3*5*7*11*13*43*47, ...

Crossrefs

A246350 gives the corresponding record values.

Cf. A246272.

Programs

PARI

default(primelimit, 2^22)
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ Using code of Michel Marcus
A065338(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = (f[i, 1]%4)); factorback(f);
A246272(n) = {my(i); i=0; while((A065338(n)!=1), i++; n = A003961(n)); i};
\\ Compute the b-files for both the positions of records (A246349) and their values (A246350) at the same time:
prevmax = -1; i = 0; for(n=1, 60690630, if((k=A246272(n)) > prevmax, prevmax = k; i++; write("b246349.txt", i, " ", n); write("b246350.txt", i, " ", k)));
(Scheme, with Antti Karttunen's IntSeq-library)
(define A246349 (RECORD-POS 1 1 A246272))